After some searching, it seems that the B67875878 has been replaced by the new and improved B67876131. Here's a link to the new one:

Part number B67876131:
Mercedes Benz Bluetooth Adapter Puck B67876131 B6 7876 6131 | eBay

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2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic