If you have a GTS with the rear fold-down rack you'll notice that there are several small rubber plugs that fill in holes in the bars. (I'm not talking about the three "bumpers" that keep the rack pieces from hitting each other.)
I recently had the rear rack powder-coated and had to remove those rubber plugs. Some survived, but most ripped when pulling them out of the holes. I assume they're in place to keep moisture from collecting inside the tubes. But considering that some water came out when I removed them, I don't know how good of a job they do. I'm in Florida near the ocean so everything is always wet anyway.
Should I replug those holes and what would make a good substitute for the original rubber inserts? They don't show up in the parts catalog. Should I use a sealant or silicone and be done with it?