it seems to work great so far. I live in the desert southwest, and we're always looking for ways to stay ahead of sun (UV) damage. Since these are so good at reflecting heat, I thought I'd try them on our Honda Odyssey. It's a bit large for the back window, but is just right for the windshield. I've had these for a month, so far, so good. Because they're so light weight, putting them on can be a challenge, even in the slightest of breezes. Once you develop a technique or have a second person, they aren't bad. To close them in the door, they will blow out unless you close the door very slowly. They're tough enough to pull snug, but they can tear if you injure them with a corner, or a fingernail. The wipers help to hold them down at the bottom. Taken off, you can wad them up and stick in a door pocket or under the seat, a good alternative to the fold-up reflectors that are always in the way. They may take a little longer to put up, but the benefits are making it worthwhile. For smaller applications, trimming them down with scissors could start a tear. Probably better to fold & tape them down to the size you need. I don't know - for what it's worth. A good product.