Always make an appointment to see the car during the day. At night you can't see all that's wrong with it. If you make an appointment with a seller, show up 15 minutes after the agreed time. Once the agreed time has passed, the seller is now going through it, thinking you are not going to show. He's probably had a few no shows, so this could make him even more anxious to sell the car. By the time you arrive, his confidence has been knocked down a notch. You are using psychological tactics and, legitimate methods of pricing a car.
Always show up with at least one other person, and make sure you have your license with you, most sellers won't allow anyone without a valid license to drive their car. It's harder for a seller to say no and challenge 2 or more people than just one person, so always show up with an aggressive companion.
If you visit a seller to test drive the car and they don't let you drive it, leave immediately. There's no reason to stay because you are not buying that car. You should never, ever buy a car under any circumstances without driving it first.
Once you get to the location, check the driveway or garage floor for signs of fluid leaks. Rust colored stains signal a leaking radiator. Black or Brown puddles and stains suggest an oil or transmission fluid leak, and purple puddles point to transmission fluid leaks. The seller of the vehicle may tell you that his car doesn't have any leaks, but a driveway or garage floor tells the truth even if the seller doesn't.
You'll likewise want to look for signs of a previous wreck or rebuild. Examine the tires and windows carefully for evidence of paint over spray. Sellers will sometimes put an inexpensive paint job on the car and then lie about it being involved in an accident. The cheaper the paint job, the more careless the body shop gets. They will get over spray all over the place, and that's your flashing neon sign that the car was in a wreck or rebuilt.
When you go on the test drive, take the seller with you and ask him questions when strange noises pop up. Listen for noises, rattles, or grinding sounds. If you hear rattling noises in the quarter panels, the car could have been in a wreck.
If the car is a manual transmission, see if the shifting is smooth and ask the seller if the clutch has ever been replaced. Clutches tend to fail after four or five years. This is all setting up the seller for the low offer you are going to make. Most people are unaware that non-automatic transmission vehicles have much lower market values than automatic.
Check the heater and the air conditioning to be certain they work properly. Drive the car in the daylight in midday preferably when the sun is hottest, to see how well the air conditioning performs. Listen closely for grinding noises when the A/C kicks in. If you hear anything like this, the bearings in the compressor are most likely worn. Take the car on a highway, main streets, and side streets to see if the car suffers a loss of alignment, or bears to the left or right.
See how well the car brakes and if you feel shaking which could indicate worn rotors. Drive sharply around some corners, and be sure your companion is writing everything down. Make a point to be certain that all the seat belts work, that electric seats work, look for missing or burned out bulbs inside and out. If the car has retractable headlights, make sure they pop up and turn on. Make sure the brake lights, reverse lights and directional lights work. Ask the seller when the brake pads were last replaced.
All of these things are designed to not only help you find out more about the car but also to reduce the value in the seller's mind so that you can get them down on the price.