Michel Wyder was the co-driver of Marc Surer during the 1986 ADAC Rallye Hessen. He was killed when Surer lost control of his Ford RS200 in a long and fast right corner, going at an estimated speed of 200 kph. The car careened into a bush, spun around and hit a tree where it burst into flames.
While the exact crash location was not published, it can be identified by video material.
In a video about the fatal crash the road where it happened was named L3291. I also identified by the curve that is seen at 0:06 in the video which is to the west of the location.