I locked my keys in it, I swear!

Next to impossible. Call 1-800-For-Merc That's the roadside assistance number. They will send someone to help you.

I own an E320 (not a CDI, but it doesn't matter in this case.) Of course, you can do whatever you want and I'm sure you'll get answers here telling you that it's very easy to do, but I'd not try it myself. If you damage something there, it will cost you MUCH more to fix, then to have a professional unlock your door. If you have an OnStar, you can call them and they'll unlock it remotely. If you do not have this service, call Mercedes technical assistance and they'll send somebody to unlock it for you.

I'm not telling you that! Your name is CarJack!

Insert the jim between the window and the car body (outside, naturally). Move it towards the door jamb until you feel an obstruction. Then move it down until it has cleared the obstruction, then twist it slightly and pull it up. You have just broken into a car...I hope it is your own!

If that fails, you'll have to get a locksmith to open the car, unless you can hook the inside release with a coat hanger.

no and i dont want to know