Why not take the car to the bad area of town and just accidently leave the keys in it and.....get it? Or park it next to a cliff and forget to set the break.....
Get lots of speeding tickets.....throw a bra in the back seat so mom finds it....keep rubbers in the ash tray..... loose the oil pans drain bolt.....Oh! Don't do that. Cars worthless then. And if the car isnt fully covered you dont want to leave the keys in it. You have to be a bad boy with that car so Ma and Pa want to sell it and get a good bike for you.
Oh, heres a good one that made my parents ground me from my car for 6 months. If you keep repeating the offence youll surely loose that car. Leave a bong on the floor somewhere. Man that will piss them off!
Good luck and keep riding!