magindat
Lemonade
I haven't had any problems with this yet. I'll pay attention to see if anything changes, but my being in New England, there might be different satellite antenna locations that work in the vehicle due to the geographic location. Kinda like that picture that was posted to show the angle of the satellites for the satellite radio for different locations in the U.S.
The Avics have built in gyros to keep on course via dead reckoning for tunnels and such, too