Tyres-Rims Combinations

I've noticed that thera are fixed tyre-rim combinations, for example the 2001-season has the pairs:
Bridgestone/BBS
Michelin/OZ and
Bridgestone/Enkei for McLaren
but in real BAR and Jordan had Bridgestone/OZ and Prost Michelin/BBS.
Is it posible to define the rim-type in a per team basis, as we can do with the tyres?

GP4 is limited to 3 textures, and that only really works with 2D rims. In reality its 2, only Mclaren in a certain slot can use the 3rd texture. It's limited, but its possible.

Thank you fongu for the quick reply.
My question was ment a little bit different, sorry if i could'nt express myself more precise:
let's say you have 2 different tex, one (tex1) for the side of the tyre with the manufacturer logo (Bridgestone, Michelin etc.), and an other one (tex2) with the picture of the rim (BBS, OZ etc.) and you combine them in one tex when loading the game via CSM or whatever ...!
Is that possible??

Then no its not possible.

Thank you anyway!