Driver's door wouldn't shut

It sounds like the latch on the door is getting hung up and/or springing back to the closed position after it is opened. If it does happen again, try jogging the handle on the door to see if that may release the catch latch. I would keep your appointment though. They will probably just inspect the latch and lubricate it unless it's faulty, they may just replace it.

Spray WD-40 all over the lock mechanism on your door. Take a screw driver and lift up on the little tab that locks over the door peg. Once the little tab is up, your door should close.

I appreciate the quick responses. When I went out to my car and got in, I don't know what made me check but I decided to see if my window was not rolled up all the way. It wasn't. After I rolled the window up (it was barely down) and tried to shut the door, the door shut like it should. Does that even make sense? Anyway, so far, so good. I am home for lunch so I'll find out when I leave to go back to work.

Unless it's some security thing, it's just a coincidence. I would spray the door mechanism anyhow. Must be dry and sticking. Should stop it from happening again.