When I first installed my GL2Way, any time I pushed the transmit button, there was a horrible squeal. I even had Pete on the phone trying to help me sort it out. In the end, it turned out what the problem was the little black box thing (yes, I know all the technical jargon and names for components) that was some inline component of the GL2Way was lying against my J&M Bluetooth unit. It was the simple fact they were touching in the trunk subcompartment that was causing it. The instant I separated them, and only by an inch or so, all the squealing stopped.
It's possible that my situation was unique, but it's worth a look. Keep that little square thingy away from everything else.
If I wasn't at work, 20 miles from my bike, I could be more specific. Sorry about that.