Well the Audi itself has got 9000 polies with a shell modifier. Without this option around 4000 polies. The shell modifier is used for showing the inside of the model too, so it automaticly covers up the inside of the model with polies. This is off course not neccesairy but just to give it more detail. But I doubt that it's possible to make the four rims together with the car and keeping the amount of polies around your estimated amount of polies. With today's modern GPU, it's quite normal to have the amount of polies I've created together with a certain level of detail. Btw, which wireframe you wanted to overview, the car of the rims wireframe ??

Cheers

Frazzle