The idea of an adapter car is basically good, unfortunately only MyWorld cars can be a "normal" model railroad dock (which will probably make the least model railway fans) - and not vice versa, because the magnet can not be turn over. We had to rebuild a MyWorld Lok, so we could dock old Märklin carriages.
Subsequent correction: Are draufgekommen that the magnetic coupling the locomotive was built wrong. The wagon is thus in order. But perhaps helps my "problem" prospective purchasers ...