Hi all, I’ve just noticed these marks on my BMW top box and wondering if anyone has an idea what they could be? I’ve tried wiping with a baby wipe as I don’t want to use anything abrasive on it. To me it looks like salt corrosion but I’d be horrified if that was the case as I’ve only ridden the bike for 140 miles since I bought it and it was washed thoroughly and the case was wiped and dried etc before putting away.