Getting his first go-cart at the age of four, Marius started his motorsport career early on. Having a track close to his home in Aalesund, Marius drove thousands of laps during his first seasons. He drove his first race in 2001, in the Formula Cadetti class, and was amongst the fastest drivers from the beginning.
Marius has had a lot of success both in Norway and internationally. He won most of the karting championships every year. In 2007 Marius competed in his first international race in the class Ica Jr. in Trofeo di Primacera, Italy. 2008 was a dream season, winning the Norwegian Cup, finishing second in the Norwegian Championship and 10th in the European Championship.
In 2010 Marius began circuit racing in the class Seven Racing, and was at the front of the pack from his very first race. And was Scandinavian and Norwegian champion already the first year. Two years later, in 2012, he took a step up to the Norwegian Thunder Car Championship(NTCC) which he dominated in his first season. Marius won the championship every year and was also the U21 Champion in 2014.
In 2017 Marius had his first year in the Porsche cup car. He started 2017 in the Dubai 24 H race and participated in the Porsche Carrera Cup Germany championship.
In 2018 he did his first podium finish in the Porsche Cup car at Sachsenring with a P2 finish behind Thomas Preining. Marius continued his success with Porsche in Porsche Mobil1 Supercup and in 2022 he had his first year in endurance racing and GT World Challenge in the Porsche GT3 R.