Oliver, Congrats!
I too just did a little service on my car, but on the front brakes, and let me tell you it is so satisfying to have done it myself, though I did have a little Help from here, the DIY E Class Brake Pad Article, was all I needed to confirm how to do it, and I was able to doublecheck it, and was able to fix a problem that was really dangerous too.
I can't wait to see the grille, make sure you tell us where to get the extra chrome strips!!
I too took mine out and painted it matte black, I plan on doing it again soon, only with semi gloss or satin finish paint, and clear coat to make it more durable.
When I did mine, I used some matte black Hard Hat Paint, which has held up well for the last 5 months, but its starting to peel off. Not the best paint to use, and I don't recommend it, but it was what I had at the time.
If you have trouble posting the pics, e-mail them to me and I'llpost em for you.
Alon