In 1997, the FIA GT Championship race car Mercedes-Benz CLK GTR was fitted with the M297 engine, derived from the M120. The 25 road cars, required by the FIA rules and delivered in 1999, had their engine enlarged to 6.9 L. There was also a 7.3 L version producing developed by AMG which was also used in the SL73 AMG, S73 AMG and CL73 AMG. The 7.3 L M297 engine was also featured in the AMG-built, S73 T Kombi, a custom-built W140 S-Class wagon for the Sultan of Brunei. Eighteen units were produced, ten of which went to the Sultan.