I'm about to buy a new car and I'm letting my dad help me out picking out which car to buy. I really want a 2008 G37 but he tells me that used cars are really unreliable. He said that they will operate for a couple months and then start to break down. Is this true?... Is there no way for me to check if the car is in good condition? (I'm purchasing at a Dealership) These cars have about 20,000-50,000 mileage. If i can't buy a used car, I would have to go with a new car and there aren't a lot of new nice cars that I can afford. But I see many people purchasing used cars and being perfectly fine with it.