Is there a way to get the wheels to rotate on a vehicle and to ALSO be able to move that vehicle (but not WITH the camera?) I'd like to keep the whole vehicle as a set, but to also have control over the rotation of the wheels.... I don't think that you can....
What could work (Depending on your anim) would be to leave your vehicle in one set then assign each wheel to a different one.
To have the wheels follow the position of your vehicle you would need to parent the position parameters of each wheel to the vehicle's position parameters. Use the pick wipe to create the expressions. You would then only need to animate the rotation axis of your wheels.
Now another way would be to create layer maps for your wheels and rotate the maps instead of the wheels. This would allow you to keep everything in one set. You don't necessarily need to map the real 3D wheels, you could maybe just attach circular objects to them and texture map the circles. Motion blur would in this case be your best friend;-)
I hope this may help. If not, give us more details on your animation or send me the project if you like.