Phil McGovern (RSPhilip on here I think) used to have his cars in carcoons in the Ranches. From what I know, he had no issues with them and security seemed to be happy enough for them to be there.
I’ve used them in the Ranches. Was asked to remove them, although nothing happened when I ignored the request. If left in the sun the plastic will degrade. My one in the sun lasted two summers (just). One in the shade lasted around 4 years.
What are you storing in it? Mine is parked in a car port in ranches and have not yet bothered with a carcoon. Seems fine in the shade but will get it under a cover now it’s mega hot.