Ive had both the Cover-zone and the Halford's car covers, the Cover-zone is far the best but of course it comes at a greater price.Jesus Apollo is expensive!
I've been using Halfords all season one on mine regularly, only after the car has had a good clean, never dirty - and never had any issues. Don't intend on using one for the colder months, car is going inside.
Ill be buying a cover soon for the Spec C.