Why are you posting this here....now? I mean, go out to your garage and pour a little more oil in, check inidcator, if it needs more, add more.
I wouldn't go back to dealer just for that, they are just going to say their sorry and add more. I bought a quart to have at home, and the M3 is gonna burn oil as you drive, always good to have some at home.
Hope everything works out for you!