John,
The tail lamps will get hot & then make poor contact. The system operates by measuring current draw from each bulb, many aftermarket bulbs don't draw the correct amps. ALSO the 2 inner front lights(parking) have been a problem since that car came out, so much so that MB designed a current drop cable to go inside of each headlight.

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MERCEDES Benz Master Guild Technician (6 TIMES)
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190E 2.3 16V ITS SCCA race car (sold)
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