I agree to an extent that people that buy their own cars generally take care of them more than people that don't, but I think what it really boils down to is you as a parent have to instill in them that a car is an expensive thing to own regardless of how much it actually cost, and that to a kid, having no respect for the vehicle they drive would result in losing the vehicle, and having to find their own way to replace or repair it.
When I was 16, I had a part-time job which would in no way help me save money to afford a car that was financially realistic to buy. In order to work more to afford things like that, I needed a car, so my dad helped me buy my first car. But he also laid it out that I would be responsible for paying for gas, repair bills, and anything in regards to damaging the car via accidents or by abuse. That alone made me not drive like a moron and hurt the car or myself in it.
