with a little dremel work the useless compartment worked out really well for the compass. it looks like it belongs stock.
calibration is going to take a little time, I got it close but I think I'll wait until my next excursion to dial it in just right.
http://www.ryandesigns.com/Vehicross/VX01.jpg
http://www.ryandesigns.com/Vehicross/VX02.jpg
http://www.ryandesigns.com/Vehicross/VX03.jpg
http://www.ryandesigns.com/Vehicross/VX04.jpg