2016 XC90: I want to leave this here for everyone to see. I live in Boston and we had a recent snow and hard freeze. One morning when it was about 11 degrees I was driving to work and the rear driver side door opened on it's own on the freeway. I took the car to the dealer and they said that an ice dam had formed on the rear door and ice was in the lock mechanism. Apparently, this is a known issue as they have service bulletins about this problem. There can be an issue with the weather stripping when there is high water pressure on the door seal. If you experience this take it to the dealer right away as they have a fix for it.