In my 2012 M37x, it sounds like the front defogger comes on and blows air at random times when I'm driving, even though all climate control functions are off. Sometimes, it seems like it happens as I'm braking to a stop. But what's weird is that when I reach my hand over the defogger vents, I usually can't feel any air blowing... so maybe it's not the defogger, but something else that's making a similar "blowing air" noise? It almost sounds like wind noise, except obviously, it couldn't be wind noise if it sometimes happens when I'm coming to (or already at) a stop and it's not a windy day. Does anyone know what this is? Thanks...

I think its the compressor cycling I hear it as well but assume it the climate control or the fresh air hooyah

Forest air? You have the tech package?

That would be my guess; what the OP is describing sounds like the Forest air. I can't remember if it works with the climate control off though, as I am always in auto mode.

Yep, my car has the Forest Air feature as part of the Deluxe Touring package; I don't have the tech package, though. I hear the noise even when all climate control functions are off, although like another poster said, I'm not sure if the automatic defogger function of Forest Air is still programmed to function, even with all climate features off.