Will treating my car cover with Scotchguard® make it more water resistant?
In almost every instance, a good car cover fabric has been treated with some sort of DWR (durable water repellency) treatment during it’s manufacturing process. The effectiveness of such a treatment will also depend on the construction of the fabric. If you can hold the fabric up to light and see small open areas between the yarns, no treatment will increase the fabrics water resistance. Adding additional treatments will not help and aren’t worth the cost.