I doubt the bulbs are DC. The dealer just want to sell a $400 visor. I replaced mine with the dealer bulb. Just open up lid exposing mirror and give it a quick tug towards you. Yes by the lid. It wont break. 10 second job replacing bulb. Bulb was $1-2. I beleve. Good luck.

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1996 E320- 18" Chrome AMG, Bling Bling Mirrors