Does the SL2 have better reception? I've tried new antennae on the car dock and it still cuts out. As long as the antannae is on top of the car, It wouldn't matter where on top due to the satellite being 250,000 miles away.
Umm. I don't know what else I can think of, except that either your radio or your car dock is bad. If you know someone that has an SL10 or 100 try their radio in your car dock, and try your radio in their car dock.