I did not know it rain in Arizona
I have used a cheap cover for 12 years, well ready two. I do have a small plastic tarp that I put on top of the cover for heavy rain.
But a few times I did not use the plastic tarp and it rained, I had water standing on the cover and the inside of the Cobra was dry.
Just my experience.
When I called Ca. Car Cover they told me their $360 cover was not water proof.
Dwight