Corrosion is a problem with the lower skirt rivets, you see a lot of cars with filiform corrosion (like worms under the paint coat) around the rivet heads, my car included. The rivets near the rear exhaust mount tended to ping their heads off until I reinforced the mount bracket on my heavier G56 exhaust. I did fit some oversize rivets, coated with a bit of jointing compound on assembly and they seem to be OK. MMC used steel blind rivets originally, sometimes with a fibre washer under the head, they still corroded. I think the rivets are the least of our potential corrosion problems 😁.
