Well, you should get yourself a couple of A500s, a serial cable, 2 copies of Stunt Car Racer, some beer, and a friend.
I know the latter is probably impossible for you, but if you manage to get a friend, you'll find it an absolutely brilliant game.
Also, if you can't find two A500s, don't worry! You can link an A500 with an Atari ST; Stunt Car Racer for the ST is serial link compatible with the A500!