Does this roof open?
Temperature control is a good point. Here in Canada we have the opposite problem of course. My Sonata Hybrid has a panoramic glass roof and when it is -30C it is much harder to heat the cabin when the glass is exposed. When I close the cover, I am able to turn the heat down, which improves the mileage for my hybrid noticeably. In an EV, I may be forced to dispense with heat altogether in severe winter weather, not a great option. The insulating value of a cover for the glass roof is an underappreciated characteristic.Just to be pedantic....I don't think UV would help against heat. It would help against skin cancer and fading. Infrared protection is what you want, like Low-E glass.