It's not all German Autobahn and it's not fast. 56:42 the sign looks like it says Parc de Sainte Croix or Cloud, both of which are in France... if not at least 10 seconds later you can CLEARLY read "Prochaine Sortie" on the sign.
Poor rental would only do 180km - 200km max but that is still pretty fast and it was a trip to Paris from Austria so it may include non-German autobahn parts:) Thanks for comment.
Do you start in the town of Karlsruhe on the Federal Highway (yellow road) 10, then the Autobahn 65 and turning for the Federal highway 9, which crosses over into France and becomes the Autoroute A35?
I just spent 5 minutes retracing my route along the roads you mentioned and yes, I'm pretty sure those were the roads. A GPS was taking me in whichever direction it wanted, but our ultimate destination was Beaune France:)