Helmut,
The quick fix for the shift linkage locking up is to not go near the place it locks up.
I seem to remember that on my friends chevy car, there were some nylon bushings that would wear causing a misalignment and the lock up. He would take a screwdriver and free them up and everything would be fine. He did replace the bushings a couple times over the years though.
I recommend the back roads, they will be a better test than just cruising the autobahn. More shifting, turning and braking.
Have you run some top cleaner through the engine? It could clean up the valves and possibly fix those differences you noticed. What were those differences, by the way?
I can only imagine what a great trip it would be driving a Bolt through Bavaria, especially the Spessarts.
Mike
