Problem: how to make car shock physic easily?

Is in Blender any way how to make car shock easily? So, for example with some special Constraint, etc. I know, I can use Rigid Body Joint, but that’s really not good for shock, because Rigid Body Joint can’t be spring. I sought some tutorials in internet, but i can’t find any tutorial for it…
I don’t want some special car shock, only simple car shock…
Does somebody know how to make something like “elastic constraint”?

At GameBlender there is an awesome vehicle solution WIP:
Advanced vehicle physics system (2.6)

A game by the same author:
http://www.gameblender.org/viewtopic.php?f=13&p=21609#p21609