You do not need visa to visit Germany ...But... while travelling, you must carry some solid_proof/Consulate_Letter etc. Most of the airlines do not know about this exception and they will not let you board without showing such proof. My friend carried a letter (originally issued by German consulate in San Francisco) so he did not have any problem in visiting Germany without visa. German authorities issued him some visa_on_arrival at their airport. They only demanded that he must have atleast 3 months of RTD validity.
I had visited German consulate in Israel prior to travelling to Germany several year ago. Even their consulate out there did not know anything about this exception. So I had to show them their San Francisco based consulate's letter. So German Consulate General (Israel) called several offices and 'could not find exact answer, but since I had this important letter so he just issued me a visa on my RTD so that I wont have to go through any hassles at POE.
So my advise is: Visit German Consulate, get this written letter and you are good to go..