combined keyframes with rigid body parts

I’m hoping someone can just point me in the right direction. My objective is to create a physics-modeled 4WD vehicle, complete with suspension etc, and animate that driving over non-flat terrain.

I’ve had a lot of success - the vehicle is modeled, suspension works, motors work, it runs great. I did it all with rigid body tools and constraints.

However… once I start the animation, it just runs open loop. I want to be able to keyframe in some steering components.

Basically - it would run straight for a while, then turn for a while, then straight again, etc. That’s the goal here.

So I’m trying to mix together a few steering arms that are locally keyframed - to give me the ability to specify when it’s going to turn left/right etc.

But i’m just having no luck combining objects that are rigid bodies with anything that’s keyframed. I think i’m trying to mix oil and water perhaps. The vehicle’s wheels are sprung on suspension parts with arms and springs. they work great. but when i try to add another control arm that has a keyframed component, either the keyframe part wont move, or the rigid body parts act is if they are no longer rigid body parts, or the constraints fail, or something. I’ve tried use empties and other things.

So basically - if some one can point me in the right direction that would be great. Again, envision a suspension rig made from rigid body parts that i want to control parts of in a key-frame like fashion. maybe there is a better way. (I’m not using the game engine for this - it’s intended to be non-realtime, with very high quality rendering to produce the final product)

thanks,
Matt