Is this a good proposition for my parents to get me a car?

I think your parents might be more amenable to YOU paying the insurance, repairs, maintenance, and gas, while they had a one time expense of buying you the car THEY think you should have. Your judgement in choice of cars is probably not too good. If you speed, get tickets, and violations, the insurance will go out of sight. If you drive recklessly, the repairs will be extensive. Same for maintenance. It's certainly a compromise I, as a parent, would go for.

This addresses almost every reason a parent would have, to deny you the privilege (responsibility) of automobile ownership.

If I were your dad, I'd actually rather pay the cost of a used car and make you pay for the running costs. However, showing that you are willing to take on more responsibility may be enough to persuade your parents to help you out.

Understand this. As a minor you may not legally own a vehicle(or anything for that matter it all belongs to your parents). You can not enter a contract to get insurance, only adults. You can give your proposal to the folks and see what they say about it, the answer is 'no' unless you ask.

My three kids knew how it was from the beginning. They buy their cars, they pay their insurance, do their own repairs and maintenance - I helped as much as they needed with that. That is how adults do it and they ought to have the experience right off the bat.

It worked out great. They are all very car-savvy (my son-in-law leaves car decisions to my daughter) and are independent people. Dealing with hassles is the only way to become strong. And you will have to become strong. Yesterday my daughter was released from the hospital, the fifth hospitalization in her family this past year.