The son of Kyle Petty, Adam was widely expected to become the next great Petty, following after his father, grandfather Richard, and great-grandfather Lee.
He drove the #45 Spree car in the Busch Series full time in 1999 after making a handful of starts late in the previous season. He finished 6th in his first race at Daytona and had a best finish of 4th that year. Adam also failed to qualify for three races. He finished 20th overall in points.
Petty Enterprises planned on giving Adam a Winston Cup ride in 2001 and planned to give him 7 starts in Cup during 2000, along with a full Busch campaign in a car sponsored by Sprint. He struggled early in the Busch season, but managed to qualify in his first attempt at Winston Cup during a race at Texas Motor Speedway. He was disappointed, however, when his father failed to do the same. Further disappointments came when his engine failed during the race, giving Adam a 40th overall finish. Lee Petty lived to see his debut, but died just three days afterwards.
On May 12, Adam was testing his Busch car in Loudon, New Hampshire when the throttle of his car stuck and sent him head on into a wall. The impact killed Adam immediately. He was only 19 at the time.
Adam's death, along with former Cup rookie of the year Kenny Irwin's at the same track, led NASCAR to mandate the use of a kill switch on the steering wheel, used to prevent such situations.
Kyle Petty, who drove the #44 car at the time of the crash, drove Adam's #45 car in the Busch Series for the remainder of 2000, and has used that number since in Winston Cup in tribute. He also used Adam's sponsor for 2 seasons. To this day, Kyle drives an all-black car in memoriam whenever he races in New Hampshire.