I have had the bonnet strap since new Richard and no visable issues...too my eyes anyway. Mine is a single pearl paint so possibly tougher than a flat paint. As DaveW said some film would work on the bonnet. My fleece (wool?) Under the strap is still soft.
I have no light scratches either, I think if it’s an every driver in all weathers the belt can attract grit...I have a small piece of PPF under the buckle part only
