If you leave a vehicle "At rest" (stopped or 'stuck' so it isn't moving for a while), the physics stop for it until it is pushed, moved or impulsed again, to reduce lag from simulating physics for everything. (See the picture, taken after moving a jeep out from underneath another)

Is there any way I can apply this effect through scripting to vehicles and objects? I think it would be nice for a "Physics Gun"-style freeze effect.