Since July 2007 I use APRS (Automatic Position Reporting System) in my car.

The current setup is:
TRX: FT-7800 (10w)
Ant: Diamond NR2-70 (1/4 2m / 5/8 70cm)
OpenTracker 2 (OT2m)
GPS-Mouse (Navilock NL-303P)

If APRS is switched on you can find my current position on:

http://aprs.he.fi/?call=DF1LON-9
or
http://www.findu.com/cgi-bin/find.cgi?DF1LON-9 
or
http://www.db0anf.de/app/aprs/stations/googlemap-DF1LON-9

Usefull information according to APRS can be found on http://www.aprs-dl.de (in german)