I just installed the AVIC-D1 and had no problem finding the speed sensor wire, but I was wanting to know if anyone has come up with a good place to hook the reverse signal wire. I want to hook this up so my display shows the reverse cam while I back up.

 

It is orange in the harness running back to the trunk under the driver's side floor board. If you have the rear compartments out, it will be quite easy to access right behind where the driver's head would be.