A police report that the robbery happened shortly before 10 p.m. Sunday at the fast-food restaurant less than a mile from the Indianapolis Motor Speedway, where Dixon had hours earlier won the top starting position for next Sunday's Indy 500.
The police report says two males ran away after the robbery and that Dixon's wife, Emma, was also in the vehicle. Officers later arrested two boys, ages 15 and 14.
IndyCar driver Tony Kanaan told reporters Monday that Dixon was making a food run for a group of drivers.
"While they were ordering with their windows down two guys approached at gun point," Kannan said. "They held a gun at Dixon's head and asked him for his wallet and his phone. You don't expect that to happen, especially here."
Dixon, who is from New Zealand, is the 2008 Indy 500 winner and a longtime Chip Ganassi Racing teammate of Franchitti, a Scot who retired in 2013 with Indy 500 wins in 2007, 2010 and 2012.
"Scott Dixon and Dario Franchitti are completely fine after being held up last night by two men at a fast-food restaurant," the team said in a statement. "We will allow the Speedway/Indianapolis police departments to handle the situation and while they conduct their investigation we will refrain from making any further comments to allow Scott to focus on the upcoming Indianapolis 500."