[Big Nodge]

Funny to see this thread from 2012 as having to turn the auto setting on when it rains annoys me in my 340i as well. In Audis auto means auto and that's what I'm used to. I get all the arguments for why BMW set it the way it is, but I would prefer to have the option to make it truly auto, just as I would prefer the option for the car to default to Sport mode.

[Fronzdan]

This is how they work. It's "normal", but I agree, they aren't sensitive enough and that's likely based on the fact that the sensor only looks at a small area for rain.

What the videos show (particularly the last one) is that under certain conditions, quite a bit of rain hits the windshield before the auto wipe decides to wipe. What I do, as suggested by others, is to reset the auto wipe sensitivity, by turning the dial from least sensitive to most sensitive when Auto is on. They seem to work better. But then having to do every time makes the "auto" rather manual.