A tip for single mothers who are taking this step; I know in this day and age, you do not hear as much about car dealers or mechanics taking advantage of a woman, thinking her too ignorant about engines and such, but it does happen. If it is more to your convenience, take a man along with you. If that is not possible, and if you do not know much about cars, read about them. Find a book in your library that shows a mechanical blueprint of a car. This way, should a seller tell you something as ridiculous as "I just had the johnson rods replaced," you will be the one laughing when you walk away without buying the car, and there is a lesson your teen has gotten for free.