Hi gFlyer,
Not my area unfortunately, but I know Lee is, or is about to go, on holiday, so though I'd better reply rather than leave you hanging.
Unfortunately, the position is that despite approaches from Lee, Garmin just won't play - i.e. they flatly refuse to co-operate with us with regard to their protocols, which makes trying to integrate PilotAware with Garmin systems extremely difficult. There are several PilotAware users on the Forum trying to get round these issues by endeavouring to 'reverse engineer' the Garmin Protocols, but so far with limited success. All I can suggest is to search 'Garmin' from the Forum 'Home' page. Hopefully one of these guys will be able to help.
Regards
Peter