I think they can be had off ebay for like 7 bucks shipped. I had one leftover from my old Pioneer 4100 from my MS3 that i purchased years back. i think there are tutorials on youtube for building one. I believe it's pretty simple, but I'm a bit lazy and lack confidence on those sorts of things.
and yes, it's the same bypass for both the bluetooth and video. it serves to "trick" the H/U into thinking the parking brake is engaged.