Sounds like the beautiful little town of Bad Oeynhausen, which I came to loathe(a bit) - I used to drive several times a year from Amsterdam to Krakow(~1300km) and literally the moment you got off the ferry in Amsterdam you were on the motorway literally all the way to Krakow.....except for having to drive through the very city centre of Bad Oeynhausen, every single time. I think last time I did that trip last year there were some intensive roadworks in that area, maybe nowadays there is a way to drive around the town without getting off the autobahn.