What kind of scratches do the suction cup and hooks leave? Will it stand up to a foot of snow? What happens when the wind hits 30MPH? Why is there someone in a bear suit putting one up?
I doubt this is something you'd want to ever use on a permanent basis. More practical for a garage kept car that occasionally finds itself in a parking lot on a hot day where you don't want to roast the interior. Maybe throw it on if there's hail in the forecast but again wind resistance? The idea is not a bad one but as always the devil is in the details of how well it has been engineered.