Lamar began racing go-karts at the age of five and won a total of 25 track championships and three International Karting Federation Regional titles. At the age of sixteen, Lamar started racing stock cars at Stockton 99 Speedway and finished eleventh in points. Over the next three years, he raced on many West Coast short tracks and won the
Shell Oil Tri-Track championship. In the year 2000, Lamar began racing in the
USAC Western States Sprint Car Series. He posted seven top-fives and finished third in points, winning Rookie of the Year. The following year, he joined the NASCAR
AutoZone Elite Division Southwest Series, and would win Rookie of the Year that year as well. He would go on to win two races and finish second in points in 2002. Lamar signed with
Kevin Harvick Incorporated in 2005, competing in a limited number of NASCAR
Busch Series,
Craftsman Truck Series and
NASCAR West Series races. In addition to two victories in the West Series, Lamar also won the
Copper World Classic at
Phoenix International Raceway that season. In the Truck Series, he raced the No. 92
Chevrolet Silverado twice, with a best finish of 21st. He qualified eighth in his Busch Series debut in the No. 33 Chevrolet but wrecked early in that race and finished 41st. He would begin racing in the Busch Series full time in 2006 in the No. 77 Chevrolet and began the season with a second-place finish at
Daytona International Speedway. After two additional top-tens in the first third of the season, Lamar's results began to fall off, and he was removed from the ride late in the season at the request of
Dollar General, who wanted NEXTEL Cup drivers in the car. Lamar attempted to make his Nextel Cup Series debut at the October race at
Atlanta Motor Speedway and at the November race at
Texas Motor Speedway in the
Carter Simo Racing No. 08 Dodge but failed to qualify for both races. After failing to qualify for several attempts with E&M in the Cup Series, he returned to the Nationwide Series to drive the No. 37
Ford Fusion for
Gary Baker. Later in the season, he signed to drive the No. 05 Ford for Day Enterprises. On October 10, 2008, it was announced that Lamar would share the Braun Racing No. 32 Toyota in 2009 with
Brian Vickers. He was again released after one top-ten in his first few races of 2009. ==Personal life==