I'm no expert, but i do know one: Andy Rothman. Andy is factory trained RV windshield expert. He's mobile out of Tucson, and I'm sure he travels closer to Yuma now and then.
I have had this conversation with Andy, and he knows how to fix your problem, which may involve gluing portions of the channel to the glass and/or the motorhome. Andy is, without doubt, the most experienced and knowledgeable tech I've met when it comes to windshield problems, and he's right in your neck of the woods:
Superglass Windshield Repair
Give Andy a call -- you won't be disappointed!