Speeding up in Autobahns or city is out of the equation. I do not know the roads well inside the city and why should I pass the speed limit in autobahns when in most of them there is no speed limit? Unlike here that I have to take risks because most of the highways are 90-100 kph of max speed, I'm not going to that on the autobahn in Germany :-)
My main concerns are the twisty roads in Kesselberg and on the way to Kufstein.
I might be able to go up to Allershausen on the A9.
As for the A5, I drove on it till Baden Baden last time and couldn't pass the 260 kph mark (with a Nissan GT-R) as there were lots of constructions and traffic and lots of speed restrictions along the way (maybe they were only suggestion as you explained now). I had a nice "race" with a tuned BMW z4 near Baden Baden. we had a few runs from 100 to 250 and it was quite hard for me the get away and my GT-R was tuned a bit as well.
Sure I'll have fun now
Thanks