A couple of options to explore for the RD mount- If you are interested in an R1 the Radenso XP visor mount is compatible. I run an R3 on one and it works great. I actually have it mounted to the headliner in my BMW to get it further up and out of the way. Another option, is a BlendMount. If you are not familiar, it mounts to to the rearview mirror neck and allows the RD to sit just below the mirror. I've got my CS set up this way. By the way, I'm in Georgia and the same rule applies with regards to attaching anything to the windshield.
In both cases I use a MirrorTap to get power to the detectors. Not really worried about dealerships not honoring a warranty claim since it would be very difficult to break a car system using a MirrorTap. I have an issue myself since I'm going from the R3 to R7, I'll need a different set-up in the BMW.