• Know the reliable history of the car and manufacture.
• Know about how long is the new car warranty.
• The average depreciation of the car.
• Experience of consumers about a perticular car model.

• Know the history of the car.
• Know the condition of the car.
• Ask the seller to bring a car to nearby workshop that you trust to evaluate the condition of the used car.
• Ask for a warranty on a used car.
• Check out the dealer before buying a used car.

If you have a problem with a car you have just purchased just follow these steps:

• See the warranty information of a car.
• If it is used car, then you will get warranty info. on the buyer guide window sticker.
• Contact the dealer for arranging service for your car.
• If the dealer is not interested to solve your issue you may file a compaint about him.

Its on you whether to do car service from main dealer or from another service station. But I suggest you should do it from main dealer because they have tie-up with manufacturers and can provide approved parts for your car.