Unless you yourself have been making repairs on the car you are about to buy, which is highly unlikely, you must get an accurate, reliable vehicle repair history before you buy. By simply viewing a used car and even by test driving the vehicle for a short distance, you may be falling prey to a less than honest car seller who has spent a small amount of money covering up damage in order to make you spend a large amount of money on the car.
Sometimes, even mechanics can't ascertain a lot of the potential troubles a car may have with a cursory examination - and in some cases, when the value of the car is not overly high, a detailed exam by a qualified mechanic may just be too costly. The only true protection a used car buyer can count on is the vehicle repair history available from any of several different places. On the internet there are a variety of choices - search for vehicle history report and see who pops up high on the list.
Know that there are choices for the type of information you can access about a vehicle's repair history. You can perform a complete vehicle history report which is highly recommended before you buy any used car but you can also request information on an auto's safety ratings, common trouble spots with any model of car currently available, average repair costs for your car and a comprehensive accident, repair and odometer history.
If you don't want to pay for a complete history, use your instinct. For instance, if the mileage seems terribly low given the age of the car, do an odometer check to see if the car's odometer has been replaced or altered by an unscrupulous seller. You can only protect yourself if you are willing to do the investigating necessary to be safe.