I should probably weigh in here as I have some first hand experience in this matter. I bought a dash came because of the way german drivers behave on the roads here, also during my commute to work everyday I drive on a country road with a somewhat sharp blind curve and more times than not when traffic is coming the other way, they're in half of my already too small lane.
The other day I was involved in a car accident in Munich while I had the dash cam running. It captured the asshole cutting me off without signaling and slamming on his brakes, then as I went to pass him on the left he merged into me, again without signaling. Barely a scratch on his car, but my car is totaled because of the damage to my suspension and steering. He was pretty pissed off that I had a camera and threatened to sue me over it and said repeatedly that I was at fault and I was in big trouble.
Because of his actions I contacted my lawyer, my lawyer informed me that with both of us claiming the other person was at fault we would most likely both be found at fault as it would be too hard to prove otherwise. When I told him I had a video of the whole thing he was surprised and asked immediately to see it. I sent him the video for review and he said that with this video we have a much better chance. He advised me to send the video to my insurance company which they were more than happy to receive and review. My lawyer thinks that with this video my insurance company won't accept my fault of the accident and that worst case for me if the guy tried to fight it in court, that the judge would firstly most likely allow it (but this is on a judge by judge basis) and that at most I would be found 25% at fault. But, with the video, it would be 100% up to the other guy to prove that I should be somewhat to blame and all costs would be borne by him should they find him completely at fault - potentially a big risk, especially if he doesn't have legal insurance.
My lawyer told me that it is not a problem to have a dash cam at the moment, the law is still somewhat unclear and open to interpretation. While not completely illegal, it's not 100% legal yet either and there will most certainly be a court decision on this in the near future. The guy who hit me was even more pissed off when I told him that I submitted the video to the insurance company and he's been threatening to sue me for (insert made-up list of shit to sue for here) over the past few days.
Oh, I should mention, that since it was my birthday yesterday, I'll be inviting a bunch of friends over as well.. perhaps if I can get enough ice together and Antje's permission, I can wheel over my kegs for everyone to drink from