Autozone has the Wahler German-made thermostat for this application. I believe it's about $15. Ordinarily I would agree that you should largely steer clear of some of the mass-retailers for Mercedes parts but the Wahler thermostat is a good one. One thing I should point out though, should you choose this route. The thermostat is mounted on a card which has the Autozone label on it. The thermostat, however, is stamped Wahler.