Used Car Buying Tips: The Complete 20-Point Checklist & Inspection Guide
Updated: Oct 9
Quick Answer: The best used car buying tips come down to doing things in order. First, check the vehicle history report, open recalls, and fair market price. Next, inspect the car body, underbody, fluids, and interior in daylight, starting with a cold engine. Then take a real test drive. Finally, pay for an independent pre purchase inspection for used car before you sign anything, even at a dealer.
The online vehicle listing photos looked perfect, and the seller sounded honest. Then three weeks later, the check engine light comes on, and the shop finds a rusted subframe nobody mentioned. In fact, most bad used car purchases happen this way, and most of them could have been caught in an hour of careful checking.
These used car buying tips are built around a 20-point checklist, split into the order you'd actually use it. Many checklists stop at the basics, though. This one also covers free safety checks most buyers don't know about, rust problems caused by road salt, and tips for buying a used car from a dealer.
Used Car Buying Tips: The 20-Point Checklist at a Glance
Stage | Points | What you check | Time needed |
Before you see the car | 1 to 4 | Budget, market price, history report, recalls | 30 to 60 minutes online |
Exterior and underbody | 5 to 9 | Panels, paint, rust, glass, tires, leaks | 15 to 20 minutes |
Under the hood | 10 to 13 | Cold start, fluids, belts, battery | 10 to 15 minutes |
Interior and electronics | 14 to 16 | Warning lights, flood signs, wear | 10 minutes |
Test drive | 17 to 19 | Brakes, steering, transmission, suspension | 20 to 30 minutes |
Final check | 20 | Mechanic inspection and paperwork | 1 to 2 hours |
Print this checklist for buying a used car, or keep it open on your phone. The point is to check the same things on every car, so one shiny paint job doesn't distract you from a problem underneath.
Stage 1: Before You See the Car (Points 1 to 4)
The first used car buying tips happen before you leave home, because the cheapest problems to catch are the ones you catch from your couch.
1. Set a budget that covers the whole cost. After all, the sticker price is only part of it. So add sales tax, title and registration fees, insurance, and a cushion for tires or brakes. At an Illinois dealer, the documentary fee is also capped, and the Illinois Automobile Dealers Association lists the 2026 maximum at $377.63.
2. Research the model and the market price. Look up common problems for the exact year, engine, and transmission, since they often differ. Then compare the asking price against three or four similar listings with close mileage. A price far below the others usually has a reason, so ask about it.
3. Run a vehicle history report. Title brands, odometer readings, and ownership history. For a free second opinion, the NICB's VINCheck tool flags cars reported stolen or declared a total loss by participating insurers. Keep in mind that a clean vehicle history report only covers what got reported. For example, a cash repair at a body shop may never show up.
4. Check open recalls. Then enter the 17-digit VIN in NHTSA's free recall lookup. Recall repairs are free at a franchised dealer for that brand, but you want to know about them before you buy, especially for airbags or brakes.
Stage 2: Exterior and Underbody (Points 5 to 9)
Most used car buying tips say to look at the body, but when you look matters just as much. Check the car in daylight, on dry pavement, and never right after a rainstorm. That's because water hides paint flaws, and a wet car hides leaks.
5. Check panel gaps and paint. Run a finger along the gaps between the hood, doors, and fenders. They should also be even all the way around. Then look down each side at an angle for ripples or a slightly different shade, which usually means body repair.
6. Get under the car and look for rust. This point matters more in Chicago than almost anywhere else, because road salt eats cars from below. So check the rocker panels, wheel wells, subframe, and brake lines with a flashlight. Surface rust on the exhaust is normal, but flaking, holes, or swollen metal on the frame are a walk-away sign.
7. Inspect the glass and lights. A small chip in the windshield can spread quickly when the temperature drops. Also turn on every light, including brake lights and turn signals, and look for fogged lenses.
8. Read the tires. Tread depth should be well above 2/32 of an inch, the legal minimum in most states. Meanwhile, uneven wear on the inner or outer edge points to alignment or suspension trouble. Then check the four-digit DOT date code on the sidewall, since the last two digits show the year the tire was made.
9. Look for leaks under the car. Check the pavement where the car has been parked, especially after a long sit. Red or pink fluid usually means transmission or power steering, green or orange points to coolant, and dark brown is typically engine oil.
Stage 3: Under the Hood (Points 10 to 13)
These under-the-hood used car buying tips don't require a mechanic's training, because you just need to know what normal looks like.
10. Start the engine cold. Ask the seller not to run the car before you arrive, and put your hand on the hood to confirm it's cold. A cold start reveals hard starting, rattles, and smoke that often disappear once the engine warms up.
11. Check the oil and coolant. Oil should be amber to dark brown on the dipstick. A milky or foamy look, or a similar film under the oil cap, can mean coolant is mixing into the oil. Likewise, coolant in the reservoir should look clean, not rusty or oily.
12. Check the transmission fluid, belts, and hoses. Where the car has a transmission dipstick, the fluid should be red or pink and shouldn't smell burnt. Squeeze the radiator hoses with the engine off and cool. They should feel firm rather than spongy or cracked.
13. Inspect the battery. Look for white or green crust on the terminals, then check the date sticker on top. An aging battery may start fine in September and quit on the first January morning.
Stage 4: Interior and Electronics (Points 14 to 16)
Of all these used car buying tips, the interior check says the most about how the car was treated, and sometimes about what the seller would rather you didn't know.
14. Watch the dashboard at key-on. Before you start the engine, turn the key to "on." Warning lights should light up briefly, then go off once the engine runs. However, if the check engine light never lights up at all, the bulb may have been disabled. Also, a scan tool can show whether codes were recently cleared.
15. Check for flood damage. Smell for mildew, then pull back a corner of the carpet and look for silt, water lines, or rust on seat rails and under the dash. Flood cars move across the country after major storms, so a Chicago listing doesn't rule this out.
16. Compare wear to the mileage. A worn steering wheel, shiny pedals, and a sagging driver's seat on a car showing 40,000 miles don't add up. Test every window, lock, seat adjuster, the heat, the A/C, and the infotainment screen while you're inside.
Stage 5: The Test Drive (Points 17 to 19)
This is the step people rush most, and a lap around the block isn't a test drive. Instead, plan on 20 minutes that include city streets, rough pavement, and a stretch of expressway.
17. Test the brakes and steering. When the road is clear, brake firmly from about 30 mph. The car should stop straight, with no pulsing pedal or grinding. On a straight road, the steering wheel should sit centered, and the car shouldn't drift.
18. Feel the transmission. Shifts should come smoothly without slipping, clunking, or delays when you move into Drive or Reverse. Many newer cars use a CVT, which doesn't shift in steps, so a steady engine note under acceleration is normal there.
19. Listen for suspension noise. Then drive over some bumps with the radio off. Clunks, knocks, or a floaty, bouncing ride point to worn shocks, struts, or bushings. Our guide on how to test drive a used car walks through a full route.
Point 20: Pre-Purchase Inspection for a Used Car and the Paperwork
Your own checklist for buying a used car catches the obvious problems. A pre-purchase inspection for a used car catches the rest, because a mechanic can put the car on a lift and read the computer. The FTC recommends an independent inspection even when a dealer has already inspected the car, and the Buyer's Guide on dealer cars tells you to ask for one.
Before you pay, also match the paperwork. The VIN on the dashboard, the driver's door jamb sticker, and the title should all be identical. The name on the title should match the seller, and any title brand like "salvage" or "rebuilt" should already have appeared on the history report.
What a Used Car Mechanic Inspection Checklist Should Cover
A good used vehicle inspection goes well beyond what you can check yourself, since the mechanic sees the car from underneath. Ask the shop whether its report includes:
A lift inspection of the frame, subframe, brake lines, and exhaust
A scan for stored and pending trouble codes, plus readiness monitor status
Measured brake pad and rotor thickness
Tire tread readings at each corner
Checks for leaks, worn suspension parts, and CV boots
Notes on any past body or frame repair
A written estimate for anything that needs work soon
Choosing a Used Vehicle Inspection Service
Generally, you have two common choices. An independent repair shop near the seller is usually the simplest option. Some areas also have mobile used vehicle inspection service companies that come to the car, which helps when the seller won't let it leave the lot. Prices vary by shop and by how deep the inspection goes, so call two or three places and ask exactly what's included.
Tips for Buying a Used Car From a Dealer
Dealers bring some protections private sellers don't, but these used car buying tips still apply on any lot.
Start with the Buyer's Guide on the window. The FTC's Used Car Rule requires it, and it tells you whether the car is sold "as is" or with a warranty. Then ask what reconditioning the dealer did and whether you can see the inspection report. After all, a dealer that stands behind its cars shouldn't mind.
Also negotiate the out-the-door price, not the monthly payment. Ask for every fee in writing before you talk financing, and handle your trade-in as a separate number. Finally, get pre-approved by your bank or credit union, so you have a rate to compare against the dealer's offer.
Red Flags That End the Deal
Some problems aren't worth negotiating over, even though the price looks good. That's where these used car buying tips pay off most. Walk away if you see any of these:
The seller refuses an independent inspection
The VIN doesn't match across the dash, door jamb, and title
Someone other than the seller is named on the title
There's structural rust on the frame or subframe
You find silt, water lines, or a mildew smell
Codes were cleared right before your visit and the seller can't explain why
Turning Your Findings Into a Decision
Most cars won't be perfect, and that's fine. So the last of these used car buying tips is about what you do with the list your inspection produces.
What the inspection finds | What to do |
Safety or structural problems | Walk away |
Worn items like brakes, tires, or a battery | Ask the seller to fix them or lower the price |
Minor cosmetic issues | Factor them in, but don't lose a good car over them |
Nothing significant | Buy with confidence and keep the report |
For negotiation, ask your mechanic for a written estimate on each item, then bring those numbers to the seller. A written estimate is much harder to argue with than "I think it needs brakes."
Outlaw Motor Company: Inspection-First Used Cars in Chicago
Outlaw Motor Company has been a family-owned used car dealer on Cicero Ave since 2004. We follow these used car buying tips on our own lot, too, so every car passes a 120-Point Used Car Inspection Checklist before it's listed. You also get a copy of the report before we talk price. On top of that, we welcome independent mechanic inspections, and there are no hidden fees or last-minute add-ons.
Not sure which type of car fits you? Our guide to choosing the best used car for your budget and lifestyle can help. You can also call (773) 343-2149 or stop by 2035 N. Cicero Ave, Chicago, IL 60639.
View Inventory and schedule a test drive today.
Frequently Asked Questions
What is the 20/3/8 rule for car finance?
The 20/3/8 rule is a budgeting guideline popularized by The Money Guy Show. Specifically, it suggests putting at least 20% down, paying the loan off in three years or less, and keeping your car payment at or below 8% of your gross monthly income. It's strict, but it helps you avoid owing more than the car is worth.
Can I inspect a used car at night or in the rain?
You can, but you shouldn't rely on it. That's because darkness and rain hide paint mismatches, dents, rust, and fresh leaks. If the only time you can see the car is at night, do a quick look, then come back in daylight before you commit.
Can you return a used car in Illinois after you buy it?
Usually not. There's no general cooling-off period for car purchases, so the sale is typically final once you sign. Some dealers offer their own return policies, but that's voluntary. That's why the inspection has to happen before you sign, not after.
Should I buy a used car with a rebuilt title in Illinois?
Only with care. A rebuilt title means the car was once declared a total loss, then repaired and passed a state inspection. It usually sells for less, but insurance and resale can be harder. So always get a thorough used car inspection, and ask for records of the repair work.
Is winter a bad time to shop for a used car in Chicago?
Not necessarily, because the same used car buying tips work in January. Snow and road grime can hide body damage and rust, so ask for a car that's been washed and look underneath closely. On the other hand, a cold morning is the best test there is for a weak battery, hard starting, or worn heater parts.
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