Whatever you do, don't use a tarp. You'll be better off just leaving it exposed to the elements.
Either use a quality car cover that will breathe (don't want that moisture to collect underneath and create a steamy sauna), or find another method like the carport/garage that allows any water to evaporate
I purchased a California all weather cover for my GP. I'm not impressed so far. It's supposed to "wisk" water away, I've found so far that it traps water between hood and hood bracing. Also my vinyl top has been wet everytime... Seems like a recipe for rust.... Not sure what I'm going to do at this point.