I parked my BMW X3 in my driveway yesterday and then went inside. I live in Oregon and it’s been cold and raining for the last several weeks. When my wife and I went to get in the car about an hour later, we discovered that the sun roof and all four windows were wide open and the interior was soaking wet. I certainly didn’t open the windows and sun roof. I’ve probably opened the sun roof once in the three years we’ve owned the car, and, with all the cold and rain the last several weeks, I’ve had no reason to open any of the windows. While the car was left unlocked, I did not leave my keys in the car and we live on a fairly private cul-de-sac. I’m baffled as to how this could happen and I can’t even come up with a theory. Any ideas would be appreciated.
Usually when I hear of this it’s a remote control issue.
Some brands have a feature for you to do just that with your remote.
different brands - different means…read owner’s manual.
For example, if it were a ‘‘push unlock button and hold for three seconds’’ method of opening the windows then it’s logical that wherever the remote was stored, purse or pocket, that other items in there pushed that button long enough to activate the feature.
Buttons that are residue sticky can stay engaged long enough to do that too.
It’s conceivable that a button multi-push method could have been activated that way too.
In the past, I have activated my own panic alarm just by sitting down in my easy chair in the house. 
Another thing that causes functional irregularities is a remote control low battery.
Try a new one.
I agree with ken green. You probably pushed the button in your pocket.
Second agreement here.