Great 2003 film (English title: “Learning to Lie”) by Hendrik Handloegten / X film, who also produced the films “Lola rennt” and “Goodbye Lenin”. From the soundtrack: e.g. Otomo by Tarwater, Inspite of Me by Morphine. I love the music playing when Helmut slips into the rain puddle, apparently it’s “Cotier Liegen Lernen” by Denzel and Huhn. Haven’t found a free full version of the song on the internet, but you can listen to a sample at Amazon.