I also use the CIPA SLIP-ON mirrors on my F150 when needed.
We use the FOLD-A-COVER G4 ELITE Brand Lockable Hard Plastic folding panels on the truck bed. This is water-tight. I have moved this bed cover from my older F150 truck to my newer model... Company sells new water seals and parts etc...

All folds up behind the truck rear window and works well with 5th wheel hitch in truck bed...

Google Image Photos
This is how we usually look using the FOLD-A-COVER when camping. All out of sight when folded up...

Camping in LOFT MTN SKYLINE Drive VA...
Roy Ken