You might want to check out Global Entry. This is a program sponsored by The Gummit that allows pre-qualified people to bypass the Immigration line.
You apply, wait, go in for a face-to-face interview, then hopefully are approved. Once approved, it really speeds up your US Immigration process.
www.globalentry.gov note the .gov domain
PS: I hope you enjoy Düsseldorf. I've been there many times and really like it there.