'99 Q rear view mirror button - what does it do?

[checksplay]

There is a button above my rear view mirror ('99 Q45) that switch between 'day' and 'auto'. For the life of me, I can't tell any difference between the two. What exactly is it supposed to do and can anyone actually notice? Thanks.

David.

[slinger5150]

Its just an auto dim mirror. When its on AUTO, it changes the reflection to compensate for bright headlights from behind. When its on DAY it stays at the same reflection. Personally, I can't tell the difference between the two. I also have medium tint on my 99Q, so bright lights aren't an issue.

[96Qowner]

On auto, it will automatically dim, gets "smokey", when it gets hit by light from the rear - helps with headlight blindness.

[paranoidjack]

On auto, it will automatically dim, gets "smokey", when it gets hit by light from the rear - helps with headlight blindness.

I absolutely love it.

[checksplay]

Thanks all, I do love this mirror. I'll have to make a point of checking when somemone's got their brights on behind me.

David

[Skibane]

I absolutely love it.

I do, too.

To me, the difference seems very noticeable - It's like the mirror puts on a pair of sunglasses whenever someone appears behind me with headlights!

Works just as well on high or low beams.