In Germany they have lots of signs for bikes basically saying be careful (I cannot read German but I got the point) especially in the back roads around the Eiffel mountains, like near the Nürburgring. I guess lots of riders take turns too fast and the Germans (at least the ones I was behind) are bad about crossing the center line in curves.
About the autobahn, there were a few unsmooth parts I drove through. But do not be confused. Compared to other national freeway systems the German autobahn is one of the best (especially compared to crappy US interstates). On the unrestricted zones you can take sweeping curves at 130+mph and not have to worry about hitting a bump. Spain also had real nice freeways (almost all asphalt) but they did not have reflectors to mark the lanes and driving 100+ at night around curves was a little stressful.
I agree, the autobahn is great, the stchows (sp?) (traffic jams) can really suck, makes LA look like a joke at times.
I had the chance to autocross on an airforce base once and the course was on rough textured concrete that was part of the taxiways. Going through the turns you could see a fine shower of rubber coming from the cars as they cornered. The traction was like no other, lots of fun!