Hi all, after extensive research on a LOT of GPS etc forums, it seems that all 2DIN GPS units with RDS can i theory decode TMC as well. TMC is a part of the RDS standard, so it is "just" a matter of piping it to iGO8 with a virtual com-port.
This work has been done, but only for Xperia and other Window Mobile units with FM-receiver.
HyperGPS is the main work that is the results of many peoples effort for about a year.
This will emulate a com port that iGO can find and manipulate for tuning the channel etc, that also emulates TMC hardware.
What I now are stuck with is to get the software installed in my WinCE5 2DINer.