is there anyone out there who can recommend a Canon repair facility in Germany? The are a few on Canon's website, only one is run by Canon. Any suggestions?
I always use Foto Maerz in Berlin because it's just around the corner from my home, but unlike Robert I cannot recommend them as far as my experiences go.
Their counter reception people are arrogant beyond belief and expect every piece of equipment handed to them to be in pristine condition (try that when being an outdoor photog). They have a hefty fee just for giving you a price estimation so you have to make a guess for yourself if the repair will be more than the lens' worth.
They also try their best no to be forthcoming with repair prices (I had a 100 non-L macro repaired, it broke down again, and they did their best to pin it on me - and there's really no way of proving different). Now that I have cps their attitude has gotten a bit better, but still be prepared to pay ~80€ just for them to pick up the screwdriver.