Guess I needed to be a bit more specific and yes I meant a fabric add on cover for off season while parked. Not sure our budget will allow us to have a permanent covered parking structure so our rig will likely be exposed to half a day of sun and elements most days.
I suppose all the plastic up top will benefit from a sun blocking cover of some sort just wondered if the a/c unit in paticular needed covering. Our last rig was a 80s vintage cabover with a swamp cooler for reference. I know plastic tends to get brittle with long term uv light so it makes sense to prolong life by covering. Just my thinking is all.
Then again there's that climb up top to install / remove . Humm. Seems I might have answered my own post. Who knew?