John Mecom Jr. was known to have as many as seven different marques not only at the same event but in the same race. In the early 1960s the Mecom Racing Team had great success in the Bahamas Speed Weeks. Roger Penske, driving for Mecom in the early years, won in the Bahamas as well as the 12 Hours of Sebring in a Ferrari GTO with Augie Pabst. The Grand Sport Corvettes were also campaigned by Mecom with tremendous results.
The Mecom Group managed ex-Moto GP Champion Kevin Schwantz from bikes and into cars and team ownership. In 1966 Graham Hill won the Indianapolis 500 while driving for John Mecom Jr. and the Mecom Team in their Lola-Ford. The team also fielded a car for George Follmer in the 1966 Can-Am season.
John Mecom Jr. backed Danica Patrick in her transition from a 15-year-old kart racer to be a professional racing car driver in 1998, by providing full financial support and securing drives for her to race in England with help of long-time family friend and former Mecom team driver Jackie Stewart. This led to her subsequent involvement with Ford and then Rahal Letterman Racing.