If you have installed a Wink mirror in your BMW and find headlight glare from following cars at night is distracting, try this. I installed a tinted plastic Sun Shield, available from Pilot Industries, 14314 Shadywood, Plymouth, Ml 48170 for $3. The 17″ shield has clamps to be mounted on standard sunvisors but will adapt very well to clamp onto your Wink.
Two notes of advice: lubricate the hinges and cut the black rubber trim where you clamp the visor on, giving a better grip on the mirror. They are also available in 15, 22, 25 and 28-inch models.