Hey Jens, I just read you thread. I also, am living in CH and have a US 1995 c4. Just got back from 1600km trip to Berlin. I have vibration at 90-110mph, but it is gets better above that range. Like you, can't get it diagnosed in CH. I am thinking about going to Porsche Singen since it is close (I am in ZH). It would be nice to chat sometime. Chances are it may be something else for me. Thanks for the interesting thread. Gruss, Kurt kurtman00@gmail.com