You mentioned this:

Radio and discs on ebay, gps antenna from dealer...

Hmmm... are you sure you got the RIGHT parts for the Xfire NAV system? Might first want to check, double check, and check again, especially with the antenna you bought at the dealer. The rest of the pieces (radio, etc) are actually from a Crossfire, yes? You might want to post up the actual part numbers that you have on each of the pieces just to make sure. Someone that has diddled with the radio or NAV system itself may have knowledge of the actual part numbers on the back of the units to ensure you have a correctly matched system. We have the factory installed NAV and it works pretty good... If you get wrong directions, you can do the "recalculate route" part of it to not have arguments with the sexy woman that tells you what to do and where to do... Uhh, the OTHER one, that is, not your wife... Mine doesn't speak so nicely when I go the wrong way... and rarely has the NAV system called me a fricken idiot.