Need help with GPS head unit install (Parking Brake, Reverse Gear & Speed wires?)

I just picked up a used Pioneer AVIC-Z140BH (2012 model) for dirt cheap to replace my old Pioneer DEH-P6900UB (2006 model). So even though its old its still an upgrade. I've never wired in a GPS receiver before and am having trouble trying to location info on where to find a few of the wires the manual says that must be tapped into.

Does anyone know where to find wires for the following...
- Car Speed Signal
- Parking Brake (power supply side)
- Reverse gear signal

Thanks!