1. Make sure that the car is on level ground before checking it out.
This is to ensure that you will be able to clearly check the tires and to see if there is anything sagging on the car.
2. Carefully check the paint job of the car, taking note of any rust spots, dents or scratches.
Look at the sides of the car from end-on for waviness; that indicates paint work. Run your finger along the edges of the joints between panels; roughness indicates residue left from masking tape.
3. Check the trunk of the car to make sure it is still in good condition.
It should not show any sign of rust, or water entry due to cracks or holes. Wear inside of the trunk indicates usage of the car.
4. Check the tires.
The tires should be worn evenly and they should match. Look at the surface of the tire for feathering (bad alignment). Bad alignment can be caused by worn steering/suspension components, the pothole down the street or frame damage. Also check the spare tire and compare the tread to the other tires if it is a full spare.
5. Takecare a frame damaged car.
Check the saddle (connects the front fenders and holds the top of the radiator). It should not be welded on either side, it should be bolted in. Inspect the bolt heads at the top of the fenders inside the hood; scratch marks indicates that the fenders have been replaced or realigned (after a crash). Look for welds inside the door jambs.
6. If you are able, try to get under the car when it is safely raised and inspect the exhaust system or any under-body rust.
Look for any black spots on the exhaust system because this can indicate leaking. This is also a good time to inspect for frame or unibody damage.
Check the exhaust with your finger. Greasy grime means important problem. Turn the car on. White vapor (not in a cold climate) is a bad sign too.
7. Check under the hood of the car for any indication of dents, damage or rust.
These can all be signs that the car was either poorly taken care of or damaged. Each fender, just inside where the hood joins, should have a decal with the VIN (Vehicle Identification Number) of the car; if it is missing, that fender was replaced.
8. Go inside the car.
Check the seats and upholstery of the car for any tears, rips, stains, or other type of damage.
9. Check to make sure the air-conditioning of the car is working well by turning it on.
If air conditioning is a must, buy a car with R134 coolant. Most cars fitted with R134 are 1993 or newer and have a sticker on the AC Condenser