What does Oppo do to keep mold out of their weekend cars/projects/not-daily-driven vehicles in wet climates?

Went for a drive in the e24 today due to the small break in the weather we’ve been having and the insanity that is the holidays when I came across quite a bit of mold. Unfortunately, there’s only space for one vehicle in the garage, and it’s usually taken by something I’m working on. Now that the e24 is nearing completion it doesn’t get much garage time, leading to it sitting out in PNW weather most of the time. I realize some of my seals are aging, but none are bad enough to allow any signs of actual standing water anywhere in the cabin, and at over $300 per door for parts, isn’t the highest on my priorities right now.


So how can I prevent this from happening again? Would a car cover help, or exacerbate the problem? Anyone have any good recommendations for cleaning it up next time I get a chance to put it in the garage? Your thoughts are appreciated!