They would have to be left on a hell of a long time to mark the paintwork. Sun will fade paint work but they aren't needed when its sunny
. Water sitting in the airbox rots the panels, particularly if your van is laid up (now thats marking your paint work!). Further more, no drip, drip, drip when i'm sleeping, You don't leave them on when your driving as they would probably blow away. Its peeing down with rain at the moment and the sheet is doing a great job and doing it simply and cheaply. used them this week when camping, weathers been bad and I am very pleased (though I have cut them down a bit). Rather polish me panels than weld new ones in!
