Guess that the Service Advisor hasn't been around MB very long. This has been a feature MB has installed since 1990 On most radios. You can disconnect by removing radio & cutting black/grey wire at pin # 1 on the power supply connector. The other connector is for speakers & will have a red/white wire at # 1. Make sure to isolate wire ends w/tape!!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
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190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
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