so they want to power the doors off the hu and run new wiring for this? thats insane. the doors are already wired. use the amp bypass and then run the bypass to the hu's speaker leads. unless u want to power the doors off a real amp, dont bother running new wiring just for hu amping.
i've never done a flipout install but i think the ebrake wiring can just be wired to ground and then u can use the monitor anytime (even when driving, yeah yeah its illegal)
oh, and r those prices in canadian?