The covers are well made and keep water out, but they will fade your paint if left on for extended periods. I left mine on for about a week and the paint under the sealing surface was faded out. I had to use rubbing compound to bring the paint back. The paint is only 2 months old, Dupont base/clear.
I purchased the cover to protect from water, leaves and dirt. When I received it, looked great. Went to install it, had a hard time, chipped paint, not good. So much pressure to set the T bolts it buckled the glass. Not happy at this point. The gasket seems to much, 1/4 inch. The Fix: Get 3 brand new razor blades, slice the gasket down to 1/8 inch, 2 cuts, 6-8" at a time. In Half. Re-install. Fits nice, looks good, and works now.
When we first received the cowl cover it looked great and has 4 pressure point instead of other makers 3. Fit was fine however the installation and removal is quite cumbersome as it requites a flat blade screw driver or coin to lock it in place. With only the third installation it no longer seals properly and allows the water from a light rain to flood into the cowl. If you just want to block air flow via the cowl this will work but if you are trying to keep water from flooding into the car via the cowl vents I highly recommend you look for another model by a different vendor for both functionality and getting the job done. I paid for this experience now hopefully this review will save others the time, money, headache and aggravation.