Based on the BMW 3.0 CS, the “L” was added to indicate the car was leicht—the German word for “light” (meaning the opposite of “heavy,” not the opposite of “dark”). To achieve its lower weight, the car’s unibody used thinner-gauge steel; the exterior trim and soundproofing were deleted; and aluminum-alloy doors, hoods, and trunk lids were used, along with plastic side windows. Under the hood was a 3.0-liter inline-six; later, a 3.2-liter was used. The wild aerodynamic aids—including a giant lower air dam, huge air scoops on the front and rear fenders, a spoiler at the trailing edge of the roof, and a hulking rear wing—earned the car its nickname of “the Batmobile.”

The CSL competed in the European Touring Car Championship’s Group 2, with drivers of the CSL winning the Drivers title six times: in 1973, and then every year from 1975 to 1979. The CSL also competed in Group 5 Special Production form, winning three rounds of the 1976 World Championship for Makes. In FIA Group 4 spec, driven by Hans Stuck, CSLs competed against racing versions of the Porsche 911 and Ford Capri with some success.