My experience comes from living in Utah, which is a very dusty place. I had a dark blue metallic Honda whose clear coat was marred by a canon custom, but high quality cover that had elastic fitting and was held in place by cables side to side and front to back. I was really surprised when I removed the cover for the first time. I worked out the finish with an orbital polish, but it was a lot of work. I’d rather not repeat the experience. Just my opinion, and I suspect the shear amount of dust was a significant factor. To be fair, living outside without a cover probably has comparable risks. My Emira will live indoors when not traveling the twistees.