Considering they are $15 for a pair of two, and they will probably last a lifetime unless you do something very stupid with them, I can't see any reason not to have them. I've been using them for a few months and I think they do what they say they do. Are they magic? No. But they are a smart design that will definitely reduce the potential for instilling swirls when washing your car. Even if it's a very small reduction, I'd say that's worth $15 over the course of many, many washes.