Excellent, that makes sense.

So, just to confirm I understand this... (and you're right, red is the hot wire)

I can put both my radar detector and GPS red wires into the crimp connector for the add-a-circuit kit, then simply ground both of the black wires for each device, and I'm all set?

Can the black ground wires from separate devices touch each other? For example, right now I'm using a bolt that goes right into the metal frame of the car to ground the radar detector (recommended from the radar detector hardwire FAQ in another thread here), can I just use that same spot and add the GPS ground wire too?

Also, I'm currently tapping into a 'switched' fuse from the interior fuse compartment just to the left of the steering wheel for my detector (again from the detector FAQ). This seems to be working fine, but I see you used a fuse that's in the underhood fuse box. Any benefits of one over the other?

Thanks for all the help.