Video headunit install help :s

[GT08]

Hi guys
I got myself a Alpine IVA-d106, and for the install there is a wire at the back of the unit that needs to be connected to the parking brake to make the video playback work. I have one question..How the hell do i do this???

Thanks for any help!!

[euroslap]

If you just attach it to Earth you'll be able to watch it whenever rather than just parked up. ;)