3-m makes a double stick tape for exterior use. I have used it to reattach trim pieces on the slide corners. They were just attached with tape which dries up in Arizona heat and they just fall off. I have lost 2 so far.
This tape is red and should work for your application. I don't remember the exact name of the tape.
2005 Sun Voyager, Safe-T-Steer
2009 Chevrolet Malibu, Blue Ox, SMI Duo,
Ohio Cardinal Gulfstreamers
FMCA Gulfstreamers International