I noticed this on a Seoul taxi-cab manufacturered by Samsung. Samsung makes cars in Korea (as part of the joint venture with Renault). And this mirror is sold after-market option for taxi-cabs (fitted by the drivers rather than the car manufacturers). The mirrors are made by a lighting manufacturer called Samjung Inverter.
if you’ve ever been on the business end of a militant bike messenger, you’ll immediately understand the value of being able to see behind you as you want to exit a taxi. Thanks to Samjung Inverter’s Younam Ha who got in touch and told me a bit more about the product.
CACI mirror – Samjung Inverter