Wow, just found
FindTape.com - so much tape! Shipping is a little high, but tape prices are good (it seems to me, anyone have a better place?)
I'm planning on getting:
1" x 60 yards of
Polyken 231 Military Grade (Waterproof) Duct Tape
2" x 36 yards AND 1" x 36 yards of
Scapa 136 Polyethylene Film Tape
The clear polyethylene film would be used to cover the gaps in the front and to secure my grill blocks (made of the 1/4" vinyl stair protectors mentioned above) in place (along with a few self tapping screws with washers).
The black military duct tape (water/weatherproof) would be to seal the lower grill block or if the clear film turns out to be inadequate after a few months. I'm more concerned about the duct tape peeling away, though it is supposed to have a stronger adhesive backing. Who knows.
Do you think these tapes will likely hold in spite of high pressure car washes nozzles and California rain/heat?