well, these cars that I am using are actually split into many MANY seperate objects. when imported into poser, poser of course does not split up the obj file into the seperate objects, but as far as uvmapping is concerned, you could load the tyre in by itself. as it happens these cars already have the tyres mapped the way you want them. theres the white-wall section, and the tyre tread section.

TemplarGFX
3D Hobbyist since 1996
I use poser native units

167 Car Materials for Poser