Harald Demuth hailed from Bad Tölz and began his racing career at the age of 20 with a Fiat 128 in his first slaloms and racing events. From 1973 onwards, there were regular rally races, and between 1974 and 1978 the first victories in the German Rally Championship.
In 1982 and 1984, Demuth won two German championships with Audi Quattro and competed in the German rally championship as well as in rounds of the European rally championship in 1987 and 1988 and between 1993 and 1995 in a Mercedes-Benz 190 E 2.3-16.