Blender basic car rig

Here's a basic car setup along a spline with auto wheel rotation and steering.
First empty  with follow path at the center of the rear wheels.
Second empty with follow path + offset at the center of front wheels
Wheels rotation by driver on X axis with 'data.eval_time' from path
4 wheels linked to first empty or car body
 the trick:
third empty : wheel rotation driver + linked to the second empty
Front wheels with copy rotation from third empty

animate the path Evaluation time
Adjust driver multiplier value according to path lenght

>>download blender file