Car rigs

It’s probably very simple, but as i have pretty much never rigged i can’t work out how to do this, Seen load of rigs for 2.49, but none seem to work in 2.5, basically i’m trying to make a keyframeable car rig, the rig i’ve uploaded here works fine, but i can’t work out how to keyframe it, as the location of anything that is parented doesn’t seem to change, and keyframing the steering empty doesn’t work.
BasicSteeringRig.blend (1.18 MB)