if you just wanted to create a map of members without correlating who owns what vehicle that would be simple enough to do. I manage a member map for one of the other forums I belong too... it's quite simple to setup and allow members to add themselves to the map, you can be as exact (proper location of your home) or inexact (point in the downtown area of your city) as you like, you can setup custom icons too...
I can start one for here if you like...
EDIT: I started one: http://www.vehicross.info/forums/sho...d.php?p=133655