Well, GTA wouldn't be GTA without the vehicles.  So here's a list of the vehicles that are on GTA3.

Cars: Banshee BF Injection Blista Bobcat Borgine Bus Cabbie Cartel Cruiser Cheetah Coach Diablo Stallion Esperanto Flatbed Idaho Mafia Sentenial Mr.Whoopee Mr.Wongs Kuruma Landstalker Emergency: Ambulance Barracks FBI Car Firetruck Plane: Dodo

Limo Linerunner Manana Moonbeam Mule Patriot Perrenial Pony Rumpo Securicar Sentenial Stretch Stallion Stinger Taxi Cab Triad Fish Van Yakuza Stinger Yankee Yardie Lobo

Police Car SWAT Van Tank - Rhino