pioneer avh-4900
#4
#6
I have (well had up until last night) the 5900. If you wire up a switch directly from a 12 volt source (accesories preferably) and then to the e-brake wire from the deck, you can just use that. the problem is that you have to hit the switch after the deck is on. I'm not sure of the name for it but it's called something like "double switching".