The rights to the first 2020 Mustang Shelby GT500 were sold at the Barrett-Jackson auction in Scottsdale, Ariz., on Saturday night for $1.1 million, but it wasn’t all about the car. The build slot was being auctioned by Ford to raise funds for the Juvenile Diabetes Research Foundation, and all of the proceeds from the sale were earmarked for the organization. Barrett-Jackson owner Craig Jackson, an avid Mustang collector who owns several historic GT500s, placed the winning bid himself. It was the second highest price ever paid for a Mustang at auction, and exactly half of the $2.2 million that...