I sell batteries and yes Douglas is an OEM supplier for BMW and Mercedes. They were a good battery company up until the end. Deka(East Penn) has taken over and their customer service is much better. Deka also makes a good quality battery. We use to use Douglas primarly but now we buy from Deka and Exide. Not real fond of Exide but Deka has increased their cost to much to carry all of their product line. However our Group 49 and other import batteries are made from Deka. Douglas still produces some of those batteries regardless of what was said by the service rep they just come out of the Deka truck.