Had a similar experience/nightmare with mine over the weekend. It's normally left on all week but the car is garaged. On one occasion I left it out for two days in the wet but washed it the following weekend and all looked fine.
Took mine off to wash the car again on Sunday and have got a few blotchy patches that don't want to polish out by hand - tried AutoGlym Super Resin, T-Cut (!), Megs Scratch-X and even 3M cutting paste but no luck yet. I reckon a machine polish may sort it though although mine's getting a full respray at some point anyway.
For anyone currently running these just be careful