tmn

This problem has apparently been solved, can't test it since I don't have the car anymore.

I found another case of this, which was also in Finland. He had found out that this problem was caused by spare rear wheel bearings, which we're non-genuine VW spare parts. We both had these bearings sold by the same Finnish spare part company changed to our rear wheels. They apparently had wrong sized ABS rings fitted in them, which somehow caused these problems. My guess is that the wrong-sized rings somehow confused the MSR system.

The only difference between my and his car was that his ABS light turned on and gave an alarm. Mine didn't.

I wanted to post this in case anyone is interested in how this turned out. It was a really strange problem I spent a lot of time trying to solve. I also wanted to thank you all who tried to solve this with me.