http://www.youtube.com/watch?feature...&v=FRC7RO2tOJQ
http://www.youtube.com/watch?feature...&v=FRC7RO2tOJQ
Might give you a bit of an idea.
It's for safety while driving and also while parked. If you ever have an accident with someone cutting infront of you etc... you have evidence pf the incident so there's no argument with insurers etc...
The camera has a parking mode and detects movement in front of the car so it'll catch anyone damaging it etc.. while you're away from the car.