There are 9 questions you should ask before buying any used car. Some can be asked over the phone or via email before even seeing the vehicle in person. Others should be asked while looking at the used car. Not asking these questions could lead to problems in your used car purchase.
1. How many miles are on the odometer? (Best asked in advance.) This helps you determine a value before viewing the car.
2. Why are you selling the car? (Best asked in advance.) There are too many variables to cover all of the possible answers but here are a few that are going to work to your advantage:
"I just bought a new car." This is good because the seller is inspired to sell quickly.
"It was my mom's (or dad's)." Again, this is a good situation because few people want to hold on to a car in this situation. They need to sell it for the cash.
"It's a gas guzzler." Some people are going to be honest. Don't be afraid to take advantage of the situation.
"It was my son's car and he relocated/entered the service/bought his own car." This might be a hard seller to negotiate with because there is no urgency for selling the car. This kind of seller tends to stick to the original price.
3. How would you describe your used car's condition? (Best asked in advance.) There are three answers that should appeal to you:
Excellent – because the car is either going to be in excellent shape, which is always a good thing or it's not and that means you're dealing with a dishonest person. Walk away from any car described as excellent that clearly isn't. The seller is trying to get one over on you.
Good – for largely the same reason as outlined above because a good used car is always a good value. Plus, an honest seller is not going to over-hype a used car.
Fair – indicates to me a seller who might not know the value of his or her car. Or, this could be a person willing to bargain. People who describe their used car as "fair" are either incredibly honest or timid.
4. Who was this vehicle bought from? (Asked when looking at the car.) The best answer is the seller is the original owner. (Regardless of prior ownership, always get a copy of registration card). All the maintenance records should be available. Plus, you don't have to worry about salvage titles from original owners, typically. You might, though, depending on the answer to the next question.
5. What kind of oil do you use in the car? (Asked when looking at the car.) Believe it or not, this is a strong indicator of how well maintained the vehicle has been. A private seller is going to answer this in three ways: Immediately off the top of his or her head, which indicates they probably did the oil changes themselves and the vehicle is well maintained. After a slight pause, ask if they can check their records. This also indicates the car has probably been well maintained. However, ask to look at the oil change records. If only one is available, be leery. Answers either, "I don't know" or gives an incorrect answer. Make sure your mechanic checks the engine out closely.
6. What are you willing to sell the car for? (Asked when looking at the car.) This lets the seller know you're not going to pay the asking price. Depending on how long the seller has been trying to get rid of the car, he or she might come back with a pretty good discount. I faced a similar request when trying to sell a 1995 Honda Civic. I was asking a fair $4100 for it. A guy said he would pay me $3000 cash for it right there and then. I turned him down, but found out later the guy did this with every used Honda Civic advertised. It was a winning strategy for him.
7. How long of a test drive can I take? (Asked when looking at the car.) Obviously you never, ever buy a used car without a test drive, even though my dad did buy a new car once this way. No reputable seller will deny you a test drive. Most, though, will ask you to limit it to less than 30 minutes. Anything longer than that makes a private seller nervous, especially if he or she needs the car for transportation.
8. Are you willing to let me get this inspected independently? (Asked after test driving the car.) Any hesitation on the part of the seller should set of warning bells in your head. Don't be swayed if the seller says no or tries to hard sell you on the car. The only answer you want to hear is, "Sure, no problem."
9. What's the last used car you sold? (Asked after test driving the car.) You might be surprised by the number of people who sell used cars as a hobby. They buy them cheaply, fix them up, and turn a tidy profit. Unfortunately, there are some unscrupulous folks who accomplish this by fixing up the cars just enough to get them sold - about.com