I was browsing Youtube and found a guy with an AVH-P6850DVD (European version of the AVH-P6800DVD) who had somehow managed to connect some kind of aftermarket navigation unit which had a really ugly UI, however, it was FULLY CONTROLLED by the HU, front panel buttons, touchscreen, and all. I wondered how he did it, so I found this:

http://car-solutions.com/Pioneer-Cable- ... CS9100.php

Although the product itself isn't of interest, it seems to imply that the following head units use the same navigation control protocol.

* AVH-3200BT (press MODE to switch to the CS9100 display)

* AVH-3200DVD (press MODE to switch to the CS9100 display)

* AVH-P3200BT (press MODE to switch to the CS9100 display)

* AVH-P4100DVD

* AVH-P4150DVD

* AVH-P4200DVD (press MODE to switch to the CS9100 display)

* AVH-P5200BT (press MODE to switch to the CS9100 display)

* AVH-P5200DVD (press MODE to switch to the CS9100 display)

* AVH-P5700DVD

* AVH-P5750DVD

* AVH-P6000DVD

* AVH-P6050DVD

* AVH-P6500DVD

* AVH-P6600DVD

* AVH-P6800DVD

* AVH-P6850DVD

* AVH-P7500DVD

* AVH-P7600DVD

* AVX-P8DVD

* AVD-W6210(Monitor)

This makes me wonder, are the old AVIC-80DVD, 9DVD, etc. navigation units compatible with the 2010 HUs, like AVH-P4200DVD for example? Is the new 2010 AVIC-U220 compatible with the old AVH-P6800DVD?

let me get this straight. If I were to purchase that product I can get gps working on my p42000? pioneer stock gps is 300 bucks and don't plan to pay that much...

Yes, that product does claim to be compatible. I have no experience with it myself.

thats neat, do you have the youtube video ? I might want to try it out. I want to know all that I need to buy for it to work.

I think this is the video:

he informs me it wont work for usa.. Singapore is only supported...

there has to be around this somehow..

I don't know if it would work, but you could always try one of the old Pioneers, AVIC-8DVD or AVIC-9DVD. They use the same connection. They're DVD-based, but not too bad. Navi features are equivalent to an AVIC-D2. Latest official maps were 2008, but it's possible to make a hybrid disc with 2009 maps from the D2. Someone on the forum once said it wouldn't work, but I'm not sure how an aftermarket unit can work with all these HUs using one protocol while a genuine Pioneer couldn't.