Mercedes-Benz made history with the 300 SL´s double victory in the Carrera Panamericana in Mexico in 1952. The 450 SLC then added a new chapter in 1978 with another double victory in the 30,000 kilometre South American Rally through ten countries. The regulations did not allow tuned engines, so the four works-supported Mercedes-Benz 450 SLCs had standard 4.5 litre V 8 engines, albeit top-of-the-range engines with 227-234 hp instead of the production version´s 217 hp.
The weighty coupe proved its stability in the course of this punishing race: despite doing a quadruple lateral roll, the Finn Timo Mäkinen came in fourth in the 40-day race which included around 6,000 km of special stages – in a car that was somewhat the worse for wear, but still drivable. The overall winners were Andrew Cowan/Colin Malkin (GB) ahead of Mercedes-drivers Sobislaw Zasada/ Andrzej Zembrzuski (P) – double victory for Mercedes-Benz.
This win encouraged Mercedes-Benz to continue development of 450 SLC rally racing cars. For 1979 they fitted a new 5.0 litre all-aluminum engine into the C107 platform and this car became known as the 450 SLC 5.0. A small handful of homologation specials were made and sold the European market.