I have one in my car - it's part of a much larger CarPC setup, but basically, it's a serial GPS unit plugged into normal x86 PC running Windows XP Embedded - and my app (it's custom) records the GPS position, along with a BILLION other things, including stuff pulled from OBDII in a text based logfile on a 2gb memory stick. Logfile gets full, it archives it to harddrive, and starts a new one on the flash drive
Car turns on, PC turns on. That simple. (not as simple as it sounds, actually - it involves all kinds of relays and inverters and insanity to do it right).
I'm yet to write anything that parses the GPS data, but I suspect it would be VERY easy to import into Google Maps.