Most of the RC car toys i have dismounted the stearing mechanism is driven by magnets. Just magnets turning + and - by power controlling what way its going to turn, i dont know if that got anything with this to do tho.. 
that dosent apply to high proformance rc cars, the onroads use toe in, toe out, and camber as a tuning aid to improve the handling. they steer with a hobby servo and have bellcrank or akerman (sp) steering. very complex. great learning tool for dampning and suspension geometry.
ok, toe in is worthless on a robot unless your going at 20+ mph ( hobby rc go between 20 to about 50 or 60 on average) and are racing on a track wear hundreths of a second matter.
edit, sry didnt read the last post