Kaspars Stupelis entered the sidecarcross world championship as a passenger for his fellow Latvian driver Modris Štelle in 2001.

The team was successful from the start, winning the first race of the season in Talavera de la Reina, Spain on 6 April 2003.

He missed the first two events of the 2011 season, being replaced by Elvis Mucenieks, but raced the remaining eleven Grand Prix with Rupeiks again.

He had a much improved 2012 season on the side of Etienne Bax, finishing second in the world championship, only five points behind winners Daniël Willemsen.

[2] Stupelis and Bax finished second in the World Championship for a third consecutive time in 2014, 18 points behind Adriaenssen and van den Bogaart.