A UPF 50+ label answers one question, but not every question about heat

I noticed that EcoFlow's WAVE Series Car Vent Kit has a UPF 50+ rating. That's an interesting specification, especially for something designed to cover part of a vehicle window.

There is a small distinction worth making here: UPF measures protection against ultraviolet radiation, not the total amount of solar heat entering a vehicle. That's excellent UV protection, but sunlight also contains visible and infrared radiation, which contribute to heating.