After retiring from racing, Holmes became the president of Chelsea Milling Company, the manufacturer of Jiffy Mixes, which was invented by Holmes' grandmother Mabel White Holmes. Holmes has also made appearances at the Indianapolis Motor Speedway on Legends Day (a day that honors past drivers of the Indianapolis 500) and other times simply as a spectator. Holmes was also likely among the drivers who previously competed in Indianapolis 500s and appeared in a special event prior to the 2011 Indianapolis 500 (100th anniversary of the first race).