Hi Banflu.

Here are some pictures of what you could do
with the doors,altough the are not from MB's
I'm sure that they will help you see what is
possible.

The first pictures are front door speaker pods,
some custom made some you can buy.

The other Pictures are for illustration only,
it shows you the work involved to make
custom panels.
As you can see,next to the subwoofers there
are component speakers and that panel is
made from original interior trimpanels.

Hope this helps.

Louis.