I use my iPaq PDA in my car with mapping software called Mapopolis (mapopolis.com) and just a basic GPS hooked up with a serial cable and it works great. Usually you can use just about any GPS (PCcard, compact flash, usb, bluetooth,...
Little update: I just used the laptop in my car by plugging in the audio out into my car's CD unit's auxiliary input and there was no buzz at all.... I could hear it when using just headphones but not when plugged into my car stereo. ...
First post here, but have been watching the thread for a while....
Anyway, just received my D610 today and so far very impressed with it. Although I also have the headphone issue, though it sounds more like background white noise...
