I have to say I didn't really enjoy the "Addendum" sequel. The first like 30 minutes are okay but it imo gets utterly boring from that point on and doesn't really deliver THAT much info...

Another film which imo is worth watching - "Kriegsversprechen" ("War promises" - the wordplay didn't make it through the translation):

German:
http://www.youtube.com/watch?v=o3s7NLQXzOY&feature=player_embedded#

English:
http://www.youtube.com/user/NuoVisoProductions#p/u/3/_mAQVQtLSK8