I got the bolt out. It was fairly stripped, but if inserted a 10mm allen socket all the way it had some decent grip, enough to move the engine on the mounts. Pounding a socket over the top was going to be nearly impossible, no room. I tried heating the starter with an acetylyne torch, since it is the only part that the bolt screws in to. I thought it would expand and release the bolt. I tried it about five times with a friend on the torch and me on the bolt. It did nothing, would not budge. I tried pounding it. Nothing. I tried liquid wrench, no movement. We heated the bolt head with the torch for about a minute, my friend advised against it thinking it would expand the bolt and make it worse. However it popped right out with minimal effort on the first try. Amazing. My advice is if it does not come loose with some reasonable effort on the first or second try stop until you can heat the bolt head with a good torch. By the way, it was much easier to remove the starter from the top than the bottom. There is practically no way on a 240D-auto to get it out from below without removing a lot of steering parts. I just loosened the brace to the manifold and the bracket for the heater hose after taking of the air cleaner and pulled it right out. Contrary to the manuals, you must also remove the back bracket to get room to pull it out. Don't forget to take the rubber plugs out of the screw holes in the back! I did and had to remove the bracket again. I, of course, replaced the bolts and the washers (with mercedes parts) for a few dollars.