This got me thinking about possible navigation solutions. I work in IT and figured that there must be a PC based solution I could use. I've got a tiny Dell 'netbook' and I figured that I could use that with a GPS 'dongle'. I thought it might also allow me to track the car and overlay the track over Google Earth and also maybe allow me to attach a webcam and make a time lapse video. The netbook solution also has the advantage of being very cheap - I already have a netbook, GPS dongles are around £30 and you can download a fully featured time limited demo version of Microsoft Autoroute for free.
So far I've tried navigating using the netbook in my VW and it's been great. Not quite as easy out of the box as the Garmin but the tracking works well and the spoken instructions are better because Autoroute actually says the road names. It also seems to have better lane guidance. It is a bit quirky in some ways, though! It took me ages to convince it not to navigate me back to a missed waypoint. I must find some more time to get used to it!