climate????
San Paulo sounds a bit like Vancouver BC, or Seattle, that kind of mild, wet thing.
I have my Rv outside most of the time, in the drier but colder interior, and would suggest either FULL covers, to keep 'everything' out, or minimal covers, and let the wind blow thru, to reduce the humidity inside the structure, where there is bound to be condensation.
As others have observed, frequent flying, washing, wax etc. are all good preventatives. I'm surprised at how much dust and other fines get into the nooks and crannies, where moisture or oil mist makes them adhere to things like glue!
This year;
flying - 8 hours
mowing, weeding, shovelling snow - 16 hours
washing, cleaning, updating paperwork, subscriptions, tiny snags - 24 hrs.
are you SURE you can't find a hangar to share?????