In fact it's made by Specialisedcovers.com. See
https://www.specialisedcovers.com/st...plus-car-cover
As it's tailor made (it has 'ears' for the door mirrors), it looks as though it's a Stormshield + .....which seems appropriate as it never moved in the strongest gale, even without the front to back tie fitted. These retail at £300+.