I've got the Avic-N1 in my car and it's possible to bypass the N1 easier than the N2, or the N3. The unit uses a gyroscope to sense when the car is in motion. It then locks you out. Depending on the software version you're running, you can just hard wire the parking brake sensor and it will still work. Another option is to run the video out from the brain into the video in of the back up camera (assuming you don't have one) and you can watch it if you switch the video option on in the unit.
If you have software version 50 or later, the parking brake option won't work, but it is possible to solder a certain portion of the circuit board to bypass it permanently, and yes, it does void the warranty. In my case, I have the N1, so it's well out of warranty. You can technically use "hybrid style discs" from Europe that have US maps and such on them, but it's pointless in my opinion, because you don't get any points of interest or anything on those. There's just no room.
Check this website out, you'll learn everything you need to know about that headunit here:
http://avic411.com/forum/
If you're still having trouble, post which unit you have specifically (the N1,N2, or N3) and I'll try to help out. Judging from the pic, it looks as if it's the N3, and if that's the case, the soldering option is really your best bet, but get someone who knows what they're doing to do it, cuz if it's a botched job, you have an expensive paperweight, as Pioneer won't warranty it.
Cheers!