I sometimes worry about what I might do if I ever get rid of my Passat... because then I might lose use of my Phatbox, and that would suck! Thankfully, at 125K miles, it's still going strong.
(and lately I've been getting a bunch of 'NO CHANGER' errors, with red/green both lit. I just unplug and replug and it gets going again).
Still, I really love this device.
If you get rid of the Passat, keep the PhatBox and get a Kenwood head unit that supports the Kenwood Keg.
Then all you need to do is load the PhatBox with the Kenwood firmware and you no longer have a problem! ;)
2003 TDI Jetta, new in January 03. ~140k miles and going strong, PB almost as old I think (may/june 03 IIRC.)
My original PB had a thermal issue pretty much since day one: I actually broke the vehicle-side harness connector I had to unplug and replug it so many times. A new (to me) PB seems to be immune.