All the Crazy Taxi games offer a variety of taxicabs for you to choose from.
These all resemble real cars, but the head and/or tail lights are arranged differently.
On the following lists, it says whose cabbie's taxi it is, and what real-life car it resembles, and in which games the taxi is featured. All taxis are convertibles.
CT1, CT2 (when completing Crazy Pyramid), CT3 'Axel' (1960 Cadillac Eldorado)
CT1, CT2 (when completing Crazy Pyramid), CT3 'B.D. Joe' (1963 Chevrolet Impala)
CT1, CT2 (when completing Crazy Pyramid), CT3 'Gena' (1965 Ford Mustang)
CT1, CT2 (when completing Crazy Pyramid), CT3 'Gus' (1949 Mercury Eight)
CT1 'Bike' (Three-Wheeled, with steel beams from carriage go around the front)
CT2, CT3 'Slash' (1957 Cadillac Series 62)
CT2, CT3 'Iceman' (1961 Lincoln Continental)
CT2, CT3 'Cinnamon' (1967 Pontiac GTO)
CT2, CT3 'Hot-D' (1937 Packard Super Eight)
CT2, CT3 'Bike' (Three-Wheeled, no steel beams)
CT2, CT3 'Stroller' (upscaled pram with dual square lights at front, roof goes down while passengers are boarding/alighting)
CT3 'Angel' (Mercury Cyclone)
CT3 'Bixbite' (1967 Chevrolet Camaro)
CT3 'Mrs Venus' (2002 Chevrolet Silverado)
CT3 'Zax' (Cadillac DeVille)
CT3 'Carriage' (wooden cart with passenger area at the back, and wooden horse on the front)
In Crazy Taxi 3, all of these can be driven on any map, providing that you have completed Crazy X.
(source: www.igcd.net)