Stated as Mercedes in the first piece but Heins may not have known the difference between a Horch and a Mercedes:-
The son of Bremerorde Burgomaster Heins, who was eye witness of a accident with which Field Marshall Rommel met in France,volunteered the following statement.
Heins was travelling in a German Jeep(Kubelwagen)from Livarot to St.Pierre-Sur-D'Ile. In Livarot he was overtaken by two open Mercedes cars,and he noticed that a General was sitting in the first one. He followed at about 550yds distance. Their average speed was about 80 to 100 kms per hour. The General who was Field Marshall Rommel,as Heins learned later on,was sitting to the right of the driver. Another two high ranking officers were sitting in the back,whilst Rommels Adjutants were following in the second car.
Source:-
http://ww2talk.com/index.php?threads/who-shot-up-erwin-rommels-staff-car-that-day-in-1944.8443/
Both knew that the Allies basically now ruled the skies over that part of Normandy and Dietrich suggested that Rommel take the back roads and use a small and less conspicuous Kubelwagen. Rommel ignored the idea and left in his large open Horch staff car.
Source:-
https://www.rcinet.ca/en/2016/07/15/history-july-17-1944-the-canadian-who-changed-the-course-of-wwii/