Rigid solar panel mount for beef racks (underside)

Need to have the beef bars

These might be a workable option: Amazon.com: BrightSource Self-Adhesive Metal Disc (3.75" Dia.) for Magnetic Applications on Aluminum or Fiberglass Truck Cabs : Industrial & Scientific

Sorry, are you saying I would need to have the beef bars in addition to the magnetic discs?

Is that to add additional securing at the top/bottom of the panels?

I think things got crossed up in the thread. I make a solar mount for the beef bars and thought I was responding about that. Not sure on the magnetic plates etc. sorry for the confusion!