nope nor have i stripped the paint from my truck to inspect for rust. the lining is a waterproof barrier, water can not pass through it. for it to rust there would have to be a tear, then only that area exposed would be able to rust. to fix is simple as a driveby to the dealer a little cold patch and good as new.that is why to remove a spray in liner is a royal pain because it bonds., whereas with a drop in if a tear or hole occurs water will get underneath and stay add o2 and you’ve got the formula for rust. but if you get holes or tear in the drop in just replace it and you’ll be good to go, i’m not suggesting he go with spray in i just wanted to clarify that they don’t rust out underneath.