This is what I use.
http://ride-on.com/
Found/noticed a nail in a rear tire about a month ago and it has yet to loss any air pressure.
It's nothing like fix a flat. Whole different animal.
"Shelby American has been performing ride and handling testing over the past several months. I am pleased to say that Ride-On will be offered to the owners for use in their Series 1's with the backing and confidence of Shelby . Thank you for all your efforts to make this happen. ”
Mark Visconti, Vice President Engineering - Shelby American, Inc.