Sofronas began his racing career in the early 1990s, purchasing a
Nissan NX 2000 which was eligible for the
SCCA SSB category. In order to make enough money to race it, Sofronas worked as a salesman at
Pitney Bowes, using the street-legal car on sales calls despite the fact it had no air conditioning unit. In 1994, he acquired an SCCA Pro Racing license and took part in the
SCCA Pro Racing World Challenge, driving an
Oldsmobile Achieva in the Super Production class, which he rented from Chuck Hemingson for $1,800. In his lone outing that season at
Road America, Sofronas finished ninth in class. Sofronas began racing under the GMG Racing banner in the early 2000s; the team is used to advertise his auto tuning service he operates out of
Southern California. He scored his first victory in the then-
Speed World Challenge in 2008 at
New Jersey Motorsports Park, en route to a fourth-placed finish in the championship. He would finish runner-up in the GT class the following season, scoring two wins and four podiums. That same season, Sofronas began competing in the
American Le Mans Series, beginning with a one-off appearance at
Laguna Seca with co-driver
Bret Curtis, where the duo finished fifth in class. Sofronas and GMG Racing would continue to run a partial schedule in the series until 2012. In 2017, Sofronas claimed a pair of titles in the
Pirelli World Challenge, claiming the overall GTA title and the SprintX GT Pro/Am title. Partnering with
Porsche factory drivers
Laurens Vanthoor and
Mathieu Jaminet, Sofronas took the SprintX title by just 13 points over
Jan Heylen and Michael Schein. He scored 11 class victories in 19 starts between the two championships that season. He followed his championship haul in 2017 with two more in 2018, this time competing in
GT4 machinery. Sofronas and co-driver Alex Welch claimed the SprintX GTS title, while Sofronas alone won the GTS class title overall. In 2023, Sofronas began his 30th season of competition under the World Challenge/
SRO America umbrella, fielding the first
Audi R8 LMS Evo II on American soil. During the
GT America Series event at
Circuit of the Americas, Sofronas tallied his 350th World Challenge/SRO event appearance. ==GMG Racing==