I don't think our climate is that unusual. Maybe being under a cover?
Do you protect your PC with an RV cover? If so, that may explain your mold problem.
We also own
THIS SATURN SKY but not enough garage space to accommodate it off-season. I had wrestled with how to protect it outside over the winter. Of coarse a well fitting car cover was one option. In the Sky forum, the general consensus was "Do Not Cover" the car, rather park it under a car port to allow the air to flow. Otherwise mold and rodent damage could become a problem.
In our particular situation, for $20 I came up with this makeshift car port under our deck that erects and comes down quickly. This method of protection has it's own issues, primarily little birds seek shelter all winter long by sitting in the wheels and on the brake calipers, and they poop a lot. At least they stay off the convertible top and paint work. I do protect everything internal and under-hood with piles of moth balls which has worked very well in keeping rodents out.
