I recently installed D3 with XM in my 2005 Saab 9-2x (this is pretty much the same vehicle as Subaru Impreza WRX).
I am not so familiar with car tweaking and installations so it took me a while to figure out how to connect (actually locate) the VSS (vehicle speed sensor) and reverse signals. All I could find at various sites were the instructions to find the ECM (Engine control module) and look for VSS there. Finally, the Crutchfield tech support emailed me a couple of diagrams that helped me locate the ECM. So to help others looking for VSS and reverse I took a couple of pics during the installation.
The ECM is underneath the carpet on the passenger side of the car, below the glove box. VSS is pin #1 on the 22 pin connector for turbo models (see pics).
The reverse wire is the brown/yellow wire located behind the passenger side kick guard (location shown in the first pic, to the right of the EMC).
Once I located the wires installation was a breeze. I placed the XM unit underneath the passenger seat. Both antennae are near the VIN label. Signal strength is excellent for both the XM and the GPS.
Hope this helps someone.
