Has anyone seen SDARS antennas (to wit, XM) that will go on an NMO mount or otherwise mount to a hole drilled through the roof of a car but doesn't cost several hundred bucks like the aviation ones? The mag-mount stuff that comes with the unit is ghetto. More than one company (Antenex, Radiall/Larsen) now makes active GPS antennas that go on an NMO mount... ---Rob