I think you need to check the speakers and see if the foam surround is still plyable. Most of the nak speakers suspensions are rotten by now and if they are then it wont be worth tring to fit them into your car. If they are still good I would take the mids out of their frames and mount them and the tweeters under the rear grills and put the crossovers that are in the frames in the trunk under the shelf. I would do the fronts in a similar fasion but put the mids in the kickpanels (there is some cutting) use a bmw speaker grill from a 84 318 then put the tweeter in the dash in the stock opening. I have done this exact job back in the late 80's and it worked out well. As far as the sub free air works fine in the 1st aid kit. Also the best way to run wire is to pull the pass front seat out and run the rcas up the center and the power up the right side along with the speaker wires.

I hope this helps!

Scott@lajollaaudio

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The Mercedes Specialists Since 1986