OK, this is a weird one. After I took the X (90D) to a car wash to get the salt off, the driver's door didn't want to close properly. It became almost impossible to close from the inside; I could close it with some difficulty from the outside. Once it dried out completely after a couple of days, it worked fine. I thought it might be a fluke, so I tried the car wash again a few days ago. The same thing happened: the driver's door refused to close, while the other doors worked fine. I finally had to enter and exit from the passenger side. Two days later, everything is back to normal.