Just wanted to let you know that Germany is the best country in the entire world when it comes to hitchhiking.
So if your on a thight budget or you just want to travel real fast, like 200km on the autobahn ( yes even the newest german BMW's or Porche's do take hich hikers) then you can do just that.
I have only done this twice some good years ago, but I can asure you, its just amazing how kind they really are. ( I even skiped the trucks and went straight for the fast cars
)
Of course it will be even easier in direction of big Cities ( Franfurt etc) & split up in groups of 2. Also make sure you get out ONLY at these highway gas stations/rest places and also be a bit blunt and just ask people at these highway stops, Is your german bad you can make a little board with the city name.
btw forget the cars with guys in green suits, they are the police and if they hear your coming from A'dam a total pain in the butt. ''Ha A'dam.. has du hash mitgenomen & warum nicht, that kind of wise guys"