Question on installing Double Din

[ChArGeR DuKe]

So I have begin installation this afternoon on my double din unit and I have everything wired and ready to go, but I hit a pothole and was forced to retire for the night.
My unit has the option to be grounded in the back and on the harness, if I have a ground on my wiring harness do I need to ground it twice? And since the Panasonic Strada double din unit has nav I need to connect the pink speed lead wire to the pink speed lead wire in my car, is this necessary and if so where can I locate it?
Also can I ground the parking brake wire to same location as the ground for the head unit?

Thank you so much for anyones input it is greatly appreciated, I am anxious to get this in and in correctly so I can post some pics.

[sLOWDOHC]

The speed sense is rarely needed but the Nav does function a little better with it.

Speed Sense dk. green/brown PCM, bottom plug, pin 32
Notes: The PCM (Powertrain Control Module) is on the passenger side firewall.

All of the other Panasonic TV's I have done in the past just needed the brake wire straight to ground. You should only need to ground the tv and the brake wire.

[ChArGeR DuKe]

I got it firgured out, the doofus sold me a harness without a speed signal lead or reverse lead. Got a new one, but its all hooked, will post some pics soon.