I think it's better ''You drive the car as much as you want''
Yes, it does sound better. But it would even be nicer to say: 'You can drive the car as often as you want (to). I don't think the official translation is standard English, but I'm not a native speaker.
"how much you want" should also be accepted.
"Quanto" for "however" is just wrong. "How much" works.