I looked into SNADS as fasteners for screens inside my rig. You can see demos by Sailrite on their application. I purchased the SNADS from Organized Obie along with their very cool net storage. You can also attach window coverings with SNADS.
As for screens for my tow vehicle's windows, I ordered from The Skeeter Beaters. The magnets come sewn into the screens. They work great as evidenced by the mosquito parade outside of my Jeep.