Instead of switching the mute wire couldn't i just do this...

Deck____3-Way-Swich________Ebreak

......................................|

...............................Ground

Sorry for my low end circuit diagram but I hope you guys get the idea, now don't get me wrong I'm not trying to say I figured this out or saying its something new.

Just looking for confirmation that this will work.

Thanks.

I don't think so. The unit uses the GPS tracking data to determine that you are exceeding a designated speed (around 10mph) and will complain. See the thread about the software mod here http://avic411.com/forum/viewtopic.php?f=34&t=17715. You still have to ground the Pbrake even with the software mod. It simply avoids having to move and ground the Mute wire. I'm not sure what your switch would gain you in any case.