grounding the wire should work, I have done some installs and tried 12v+ and ground, no harm done to connect the wrong thing, but I seriously reccomend a switch that will control it, all it would have to be is a small toggle from Radioshack

hehe... everyone is forgetting to ask the obvious... do you have a volt meter?

if it has voltage... DONT GROUND IT...
if not... id say your ok

but as dan said... we do not condone breaking the law... pushing the limit but not breaking it hehe... if it was me, id wire it correctly, tap the brake enough to let it click and use it when i wanted to drive while watching something but bewarned that causes wrecks

well as soon as you put it on to open the switch the BRAKE light will turn on and if he has the graphical DIC it will say Parking Brake Set I think

Yeah I understand what u guys are saying about the laws and all. But I mainly got it for my son he's two and he just hates being in the car and also my e brake doesn't just barely click it has to go all the way down to lock and I talked to a guy at best buy and he told me to hook it up to the ground on the ebrake wire but what I don't understand is how is there a current coming from the ground to let the radio know the e brakes down if there's no power coming from a ground or a signal the guy told me though that the e brake wire is just a negative wire so I'm guessing I could just run it to a negative connection some were on the car

there should be 2 wires on the park brake switch, 1 will lead to ground and the other has nothing when the switch is open, a test light would help on that one, but if you can test one and its not right just switch, or just look for a ground somewhere, even the head unit ground