Personally, I prefer a patch on the inside, but the mushroom head plugs work great too and don't require dismounting the tire. If you go that route WARNING: Do NOT let the tire repair place gouge out the hole with a "cleaning" tool (that's how almost all of them do it)--that just tears up additional belt fibers. Just pull out the nail/screw/whatever, and insert the patch (and if it's a screw, try to get hold of it with pliers and unscrew it to avoid more damage). Swab some rubber glue around the hole as you press in the plug and it will seal out any water. I wouldn't worry about water causing rot in the belts--you're not going to get 60Kmi and 5 years of use out of those tires anyway. And even for track use, I do not worry about patches or plugs for simple holes. If you're planning to go 200+ MPH in the Mile, well, you should be running Hoosiers anyway.