An A/C cautionary tale ...
Inspired by David's "A bike rack cautionary tale"....
Many A/C unit covers are held on by four fender washers with acorn nuts.
Bouncing down the road can cause the plastic to crack around the washers, resulting in the loss of the cover along the highway.
Solution is two pieces of flat aluminum 1/4"X2" stock cut the length of the top of the cover. Each with two holes drilled so that each length replaces two of the fender washers (Front to back).
This will stabilize the top and prevent the cracking which causes the loss.