As far as I know, the harness is always the same.
One reason why a PCM2 retrofit is possible on MY 2003 cars.
There seems however to be a difference on cars before MY 2003 which are equipped with or without PCM. One reason why a PCM retrofit would be pretty expensive on before MY 2003 cars (a PCM
2 retrofit is impossible anyway).
I'm sure that some manufacturer will come up with some kind of MOST Bus adapter for non-MOST Bus equipped cars but right now I have no knowledge of such a thing.
Thanks for the flowers but I'm not sure I know that much about Porsche.
I get some infos here and there and I try to make logical connections. Nothing more and nothing less.
We're hoping for official Porsche support but at this point it is practically non-existant. We still have high hopes however.
Can't tell you much about the Traffic Pro and cost but let me give you some advise: there are VERY good NAV systems out there, some with DVD Navigation (Alpine, Pioneer, etc.).
If a knowledgable and experienced HIFI shop does the install (messing up with the wiring harness is pretty easy, be careful), you'll be very very satisfied.
The Traffic Pro is a nice product but maybe not what you're looking for if you're used to the PCM.