Can i link an object to a moving object to save performance ?

Hi All, i'm building a Historical simulation consisting of cars, buses, buildings and pedestrians. i want to know -

i thought the best way to save on performance was to build 2 or 3 wheel sets (bus, sedan,hatchback Etc ), each consisting of just 4 wheels inside an object box and coding for traffic behavior. i would then link different wheel-less vehicle chassis ( i'm planning on around 12 models with scripting to change the colors ) to the 4 wheel objects. i realize i'm still essentially creating 12 different objects but would this method be optimal ? or if somebody knows an even better way, please post me a link.

cheers