In 2007, he signed a full-season deal to join his brother at Andretti Green Racing and to be the full-time driver for their new ALMS P2 class Acura entry with teammate Bryan Herta. Dario Franchitti, Tony Kanaan, and Herta teamed up to win the P2 class in the first outing for the team and the car: the 2007 12 Hours of Sebring. Marino started with the team at the next race in St. Petersburg. Both Franchitti brothers left the team after the 2007 season and while Dario went to NASCAR, Marino continued in the ALMS, switching to Dyson Racing's Porsche RS Spyder, partnering with Butch Leitzinger.