OK, will try to answer several questions I've seen addressing the Winegard Rayzar Automated HD OTA Antenna and its compatibility with a "busy" RV roof. Our Winegard Motorized Sensar antenna failed on our last trip, in the up position of course!! I did a search for a replacement and discovered they are obsolete. I found the Winegard Rayzar Automated HD antenna but with much discussion and debate as to its viability on a coach with a "busy" roof. In our case "busy" is defined as 3 air conditioner/heat pumps, a domed satellite antenna, 2 full length Girard awnings and awning facades on the driver side and 3 Fantastic Fans with rain covers. I ordered the Rayzar 8500 from Amazon and it arrived this AM (Thanks Amazon Prime).

I pulled the Sensar antenna and discovered just a 2" hole penetration for the coax and the power cable for antenna motor. The "X" represents the placement of the new Rayzar antenna so you can see the relationship to the Girard awning to the right. (Note: I spoke to Winegard Tech Support, they stated maintaining a 12 inch clearance with surrounding metal would be sufficient for the antenna to work without interference.)

I connected the 72" coax to the existing coax with a female coax coupler (would be nice if Winegard included one in their retrofit kit).

I then placed the Rayzar Antenna in the middle of the coach roof ensuring adequate clearance from surrounding metal objects.

I then went into the coach and replaced the Sensar power panel with the Rayzar control panel.
Prior to removing the Sensar antenna I manually placed it in the "up" position and performed a TV channel scan; the TV reported 24 channels. Of the 24 channels, several of them were unwatchable due to pixilation and interference (I could not aim the antenna as the motor is dead AND I'm doing this in a metal garage with the doors open.)
After installing the Rayzar control panel I fired the system up and executed a channel scan. In about two minutes the LEDs stopped and the panel readout indicated 5 RF frequencies were located. I then performed a TV channel scan; the TV reported 25 channels. While stepping through the channels I discovered 1 that was pixilated, all the others were viewable with outstanding reception. I did not try to fine tune the antenna.
I will complete the installation of the antenna on Wednesday when the Dicor sealant arrives but for now, with a data point of "one" I'm very impressed with the initial performance!