'Licence to Drive' with Corey Haim and Corey Feldman. Film was about him borrowing his Grandpa's Caddy and smashing the bejesus out of it. Came home, about to get a b*llocking, and redeemed himself by driving his pregnant mother to the hospital, backwards (as you do).
His girlfriend (named Mercedes) drove the white GTi cab.
(Film nerd in the house!) :-[