well... most importantly (for the most users) is to have access to the address search and so forth. These options are ALWAYS enabled via VoiceCommand (assuming that you have bluetooth unit hooked up)
If you don't, you have to wait until Thursday or so. I've read on another thread in the Hacks forum that Pioneer is releasing some sort of update next thursday which will enable a 2-wire bypass.
00igloo,
You installers probably did you a favor and grounded your e-brake. If they did so, you should see a warning about incorrect e-brake connection. That working pops up only when you start the unit.
Have fun guys!
dimaj