Most of the autobahn is no fun. Because its constantly bumper to bumper.
But then...there are some stretches of it in southern Germany which are simply glorious. I remember flying down a 4 lane Autobahn, going as fast as the Mercedes would go, and there was no speed limit and hardly any other cars. Plus the scenery and the views were breath taking
I'm not sure I would still have it in me to do this now, I've been away from there (and fast driving) to long..