I've used my Ipaq 5555 for in car GPS. Worked like a charm with both Navman GPS sleeve and TomTom bluetooth. Highly reccomend. The only down is the speaker in the Ipaq is very low - an issue with those models, so you wont hear the voice prompts too well.
You can get (just) BT tomtom receiver for about 180 USD on ebay or with software from tomtom website for 300.
Navman is good, but they dont have the 3-D (yet) like tomtom has. check out both websites to see what look you prefer, - the prices are about the same and quality is very high on both devices.
I personally prefer TomTom BT recevier - small and easy to place on dashboard, no suction mounts to the winshield unlike Navman. But you'll need a car vent mounted holder for the PPC - only 10 bucks |