Luis Miguel "Chapulín" Díaz Castell is a Mexican racing driver who competes in the American Le Mans Series for Level 5 Motorsports. He won the 2009 American Le Mans Series LMP2 class drivers championship alongside team owner Adrián Fernández, and was runner-up in the 2005 and 2006 Rolex Sports Car Series DP drivers championship. Díaz also has an extensive open-wheel racing background.

Level 5 Motorsports was an American auto racing team founded in 2006 with illegally procured funds by racing driver, money lender and later convicted racketeer Scott Tucker, currently serving a sentence of 16 years and 8 months in federal prison. Level 5 Motorsports competed in the United SportsCar Championship and Ferrari Challenge, having won multiple American Le Mans Series championships and endurance races including the 24 Hours of Daytona, 12 Hours of Sebring and Petit Le Mans. Level 5 Motorsports began with Tucker competing in the Sports Car Club of America and Ferrari Challenge Series. In 2007, while continuing with SCCA and Ferrari Challenge, Tucker entered several events in the Rolex Sports Car Series and Koni Challenge Series with co-driver Ed Zabinski. Tucker also competed in the IMSA GT3 Cup Challenge.