Attached Link: Car Animations

See the little triangle next to the rotate tool? Pull that down to object space. The rotate the wheels a couple times between the keyframes. Be warned, because bryce has no motion blur, the wheels may act strangely.

well yes.. but the car is also moving and thus if i dont keep the wheels grouped... it leaves the actual position:(

First, go to the edit menu selection. Then go to the pulldown next to the rotate control. Select "object space". Then select the wheel and the tire. You will probably have to ctrl or ctrl-shift select the wheel and tire so as not to affect the continuity of the entire vehicle grouping. Then (provided your model loaded aligned to the Z-axis properly) you can rotate the wheels on the x-axis. Note that for this to work right you should be in object space mode. For the front wheels, the steering direction can be controled by rotating on the Y-axis. Likewise, one could also regroup the vehicle separating the wheels and tires from the overall grouping. Then make wheel and tire groups which are child objects of the vehicle. Sometimes this is an easier way to do things. It can be easier to control heiarchy using the parent-child system rather than the regular grouping. Also note that by having two separate family groupings for the front and rear wheels you could also simulate slippage (different spin rates) between front and rear sets. This allows you to simulate different powertrain setups (fwd/rwd/awd.) Getting wheel speed and vehicle speed to synch is tricky, you could do it mathematically based on wheel circumference etc. - but trial and error should work just as well. Also note that it can be desirable at times to simulate slippage with either spinning or locked wheels. Hopefully that should help a little bit.

Somebody earlier this month asked the same thing. Do a search on the forum for cars or wheels and you should find some useful info. What pauljs said is essentially correct. You can right click on your scene and a list will pop-up of all objects under the cursor, then you can select the tires without having to ungroup. When animating the rotation try doing with auto-key off, otherwise you'll get unwanted keyframes that will hinder animating the rotation. The auto-key is in the lower left corner on the animation pallette there's a little triangle.