If you take out the left-hand pocket, there's a 2-pin connector there that can be hooked to a cigarette-lighter socket that you can mount in the pocket. The socket and connector can be had at Cyclemax. That's how I did it anyway.
This may not be the answer you are looking for, but it worked for me: My "GPS" is my Android phone (Casio G'zOne Commando). One reason I got this phone, is that it is waterproof. Since the connection to charge is on the right side (as I'm looking at it), I put a 12 volt socket in the right pouch. My socket came with a long enough cord, so I ran it all the way to the battery and put a fuse in line. It is simple and works great.
The portability and versatility make it an attractive choice for me, especially since I don't spend enough time on the bike to justify having a dedicated unit hard wired. Since my headset is Bluetooth compatible, I can use the phone while riding and people on the other end think I'm sitting in an office. Google Maps handles my navigation and I've found the unit to be very capable. The biggest shortcoming is me- I've still only scratched the surface of what this set up is capable of.
The only downside is that I haven't figured out how to interface my wireless headset with the CB, but since I don't do group rides and haven't used a CB in 20 yrs, that's no big deal.
The major consensus seems to be the left pocket for the cig plug, but I wanted one more easily accessible so I mounted mine in the CB panel, its hooked to a EC fuse block as I wanted it to be 15amps....the black button is the garage remote...Ive since added a kury battery meter next to the black button...good luck...
I would also suggest wiring the Socket so that the power is Always-ON... That way you can use the gps while parked, rather than having to turn the bike On. Note that, this way, you'll have to be sure to always turn the gps OFF, to avoid draining your battery when parked.