Lars began his career as a standout player in B.C. High School Basketball. He was named MVP of the "AAA" High School Boys tournament in 1971-1972 and he won the Vic Andrews Award as the B.C. High School Athlete of the Year in 1972.

Lars attended the University of Washington where he lettered all four years with the Huskies. During his time at U of W he received the Bob Wurster Award as the team's most improved player and the Hec Edmonson Trophy as the team's most inspirational player. In 1976 he played in the NABC East-West All-Star game in Oklahoma and was named to the NCAA PAC 8 All Conference Team. In the same year he played on the Canadian Mens Basketball team at the Montreal Olympics.

Lars was drafted 39th overall by the Chicago Bulls, becoming the first player from B.C. to appear in the modern-day NBA. He played briefly on a number of teams before joining the Seattle Supersonics in 1978. Seattle went on to win the 1978-79 NBA Championships.

After his NBA career, Lars played European basketball in Italy and Spain. In 1981 he was named Player of the Year and scoring champion of the FIBA First Division Spanish League.

Most recently, in 1998, Lars was a member of the team that won the bronze medal at the World Masters Championships in Portland, Oregon.