I have started mounting my Nex 7000 on my scion.... Im missing 2 wires the speed which i know Im gonna have to run a wire to the engine and my reverse light signal.... That reverse light signal wire i cannot find anywhere I am considering having a wire from my taillight reverse straight to the purple wire on the avic nex 7000 what do you guys think?  

I just notice I posted this in the wrong place..... IM sorry. Can a admin please move this? or should i delete it and start over?