June 2006, he appeared on an entry list for a Busch Series race at Nashville Speedway as the driver of the #56 Mac Hill Motorsports Chevy. There was some initial doubt as to whether or not he was officially reinstated; however, multiple reports stated that a NASCAR official confirmed that he was reinstated. He drove the car in non-companion events the team entered; however, Kevin Lepage was still the driver most race weekends. He participated in five Busch events before being suspended indefinitely on September 11, 2006. Camping World Truck Series Grubb began his career in the NASCAR Truck Series running for the family owned Grubb Motorsports. In 1996, he had two starts in the #55 Virginia is for Lovers Chevy finishing his first start on the lead lap in 18th after starting the race in the 8th position. In his second start, an accident brought his race to an end after just 48 laps. He returned to the series in 1997 for one more start where he finished 13th in an unsponsored Grubb Motorsports Chevy at Nazareth. In August 2006, he took over the 15 truck for Billy Ballew Motorsports after Kyle Krisiloff left due to a dispute with Kyle's dad over sponsorship. However, that effort ended with the drug suspension in September 2006. Substance abuse test NASCAR's Substance Abuse Policy allows NASCAR to administer drug tests virtually any time, anywhere, based only on "reasonable suspicion." Grubb failed a substance abuse test in March 2004, and was inactive until June 2006 when he was reinstated by NASCAR. One of the conditions of his reinstatement was random, unannounced drug tests, a condition to which he agreed. He participated in five Busch events before being suspended indefinitely on September 11, 2006, when he refused to take a drug test following a second-lap crash at Richmond. Failure to take the test resulted in automatic suspension. The next day, Grubb claimed that his failure to take the test was a result of confusion following a concussion suffered during the race, and offered to take a drug test at that time. He was cleared by the infield hospital following the crash, but was diagnosed with a concussion the next day at a local hospital. He claimed no memory of the refusal to submit to a drug test. In a comparable situation, NASCAR driver Shane Hmiel was offered a chance at reinstatement after a second