Off-roading game so far

This is part of my off-roading game i have to make for school, its only a little bit done. i do have a couple things im stuck on. 1.) i cant get the Jeep and rock to Hittest. i want the jeep to shake when it goes over the rock 2.) also im gunna have some of the rocks get the jeep stuck, and when that happens youll be able to use a winch to pull your self out by pushing space, so my question is can a stoped movie clip play when space is pushed? thanks so much for any help