Her car is a late eighties / early nineties VW Polo - I think you are right about it probably needing non-silicon based fluid then. I will check for the DOT-number tomorrow
Thanks a lot for your replies!
@Finum Fit; So, have you ever been to Stavanger yourself? Let me know if you come by sometime so that I can show you a proper slow-a$$ European car*
*mine