We have a new GPRS Textracker vehicle tracking product that does not require a server and talks to MapPoint 2004 directly. A free trial plug-in is available for demo. www.text-link.co.uk/demo
The Textracker can display Direction and speed on MapPoint every 5 seconds. You can see your vehicle move along the streets in Real-Time.

Comments and suggestions for improving the system are very welcome.