Okay sorry to keep bumping this with the same question, but I have been doing some research into the wiring.
I'm getting mixed signals as to what I need to do to ground the parking brake wire.
On one hand, a lot of people say just ground the parking brake wire on the harness to a mounting screw - if that is the case that's awesome.
However doing some research has revealed it may not be as easy with pioneer.
A lot of people have said they need to ground the parking brake wire and add a switch, others are saying you need to ground the parking brake wire, then add a wire to part of the harness you don't need (I.e. automatic aerial) and grounding that, as well as not hook up the speed sensor:
http://studio711.com/cs/blogs/ben/pages/28055.aspxAs said in that blog, the extra grounded wire "disables the internal gyros".
That went above my head, but I'd guess that with the Aerpro harnesses, not connecting the speed sensor wouldn't work out to be easy.
Has anyone with a Pioneer HU had success with just grounding the parking brake wire?