Please note that from Wednesday, May 20th until at least Monday, May 25th (Whitmonday, public holiday), two thirds of all German long distance trains and almost 90% of the local trains and S-Bahns will not operate.
Those of you with urgent travel plans please book your rental cars or bus tickets ASAP as prices will skyrocket in the next couple of hours.
All German national bus lines: http://www.busliniensuche.de
Rental cars meta search engine: http://cars.momondo.com