FIA regulations permitted the use of 'special bodies', so a small number of Sebring Sprites were subsequently fitted with coupé bodywork in aluminium alloy and glassfibre.
Later, other Sprites received similar alloy bodywork from Alec Goldie and Fred Faulkner of the firm Robert Peel Sheet Metal Works (commonly known as 'Peel Coachworks').
[1] For the long-distance race at Sebring, Florida, in March 1959, the BMC Competition Department entered three Austin-Healey Sprites in the 12 Hours Grand Prix d'Endurance.
Larger twin 11⁄4-inch SU carburettors gave the engines more performance and special twin-plate racing clutches took the drive to straight-cut close-ratio gearboxes.
The Healeys subsequently offered to bring customers' Sprites to a specification similar to that of the Sebring cars, though using twin 11⁄2-inch SU H4 carburettors and a complete replacement braking system by Girling.
In the twelve-hour race, Sprinzel drove a prototype Sprite with a GRP Falcon kit-car body, built and entered by the Donald Healey Motor Company, to another class win and 41st place overall.
Sprinzel Sebring Sprites were soon being built for racers Cyril Simson (S 221), Chris Williams (52 LPH), Ian Walker (WJB 707), Andrew Hedges (410 EAO) and for BMC works rally driver David Seigle-Morris (D 20).
In the 12-hour race, Sebring Sprites were driven by Ed Leavens, John Colgate, Joe Buzetta, Glenn Carlson, Cyril Simson and Paul Hawkins to strong performances, finishing 2nd, 3rd and 4th in the 1150 cc sports (prototype) class and 15th and 25th and 37th overall.