Already knew this when it was recommended to put re-wearable masks in direct sunlight for a period of time.
My wife, an RN all of her adult life and still a great one at age 80, showed me how to make sure our cloth masks would be virus/germ free for our next trip to pickup groceries.
She had me park our vehicle in the sunlight, facing the sunlight. Then, we lowered the windows about 2 inches.
Last we put our masks upside down on the dash.
So by the next time we put them on, they should be germ and virus free.
Glass filters out some UV frequencies - but maybe not the virus-killing ones?