I want to hook my phone up to the car and use the speakers for the voice output and use the navigation's microphone for the voice input. I know there's a wire on the wiring harness for the N2 that says it's for cell phones, but I have no idea how to hook this up. Any ideas?

There's no functional bluetooth module for the n2. Best bet is to get a kit like the parrot 3100. The "cell phone wire" you speak of is a mute input. That's meant to be hooked up to a separate handsfree kit. When that hands free kit is in use it, it sends a ground signal to that wire and when the n2 sees that ground signal it mutes the audio output.

Pioneer pretty much wants you to drop $2000 a year to have all the cool features. I mean horrible sirius, ipod and bluetooth on the n2. Come on!