Like most motorsport people , Cullen began his career in karting . 2012 joined Cullen in the single-seater racing and competed in the British Formula Ford . With two third places as the best results, he finished the season in sixth place. In 2013 , Cullen took part in two Toyota Racing Series events in New Zealand earlier this year . Cullen then received a cockpit for the 2013 season of the GP3 series at Marussia Manor Racing . There he competes with a British racing license. In contrast to his teammates Tio Ellinas and Dino Zamparelli, he remained without points and finished the season in 29th place overall. In 2014 , Cullen played his second GP3 season for Manor. Cullen was again without points, in contrast to his teammates Dean Stoneman and Patrick Kujala . Manor stopped racing two racing weekends before the end of the season. Cullen joined Trident Racing for the season finale . At the end of the season, Cullen was in 25th place overall. Two 13th places were his best results.