Not sure about the room on there.. Id try an extension and impact gun it off... Looks like crappy access in the first place and sometimes its troublesome to be able to put alot of power/torque on the bolt properly when your in a akward position..

If extension wouldnt work add slightly bent U joint adapter and should have enough room under the driveshaft.

Here's another tool that might help in a different way.

http://www.amazon.com/Knipex-8603300.../dp/B000Y03968

Knipex 12" Pliers Wrench. An amazing tool. Maybe my single favorite tool. Once you get past the purchase price, you'll find you use these in many jobs where they excel for different reasons.

In your case, the fact that it can squeeze against opposing faces very tightly may allow it to succeed. At least it will not make things any worse.

have a fire extinguisher handy, (that eliminates the question of "what happens if something catches fire?...........)
Ive also found in some cases the socket profile is flared out a bit at the edge, so I have a few that ive ground flat with a bench grinder. then I take an old beer can, cut out a circle about 1/2 inch bigger diameter than the bolt head, place it on the bolt, lightly tap the socket on, and with any luck the increased grip pressure will allow just one more removal of the plug! :)
good luck! and order a new plug while youre at it!!!!

Different tranny. I can remember when I loosen my fill plug.... It was soo tight. I ended up holding on to the rear suspension some how and kicking the breaker bar! Kind of like I was kick starting a motorcycle lol. One good kick and it broke loose:)

Heat and a real penetrating oil. WD-40 isn't going to cut it. You want Kroil, PBBlaster, weaselpiss (ATF+acetone).

Do yourself a favor and source a new plug, preferably with an internal hex.

I've got a drawer full of Knipex pliers/wrenches. Full Cobra jaws and flat. Wouldn't use it for the bolt in this post.

I find the flats awkard if I had to use them. However, the small 6" handle flats cobras were a lifesaver. Can't remember the exact details but I was plumbing in a new hot water tank, and running black pipe, etc....and I all remember was, as much as I hated my ~knipex flats~, I was glad I had it for that job.

Yes going by BMW tomorrow

The dealer had to special order the plug and won't arrive here until Tuesday so I'll be giving it a try then.

Always frustrating.

Don't know this part exactly, but it always seems to happen to me on "one time use" bolts, making me think the dealer isn't really replacing them every time...

Just keeping you guys posted: I went by BMW to pick up the plug and again was given the wrong plug; an oil drain plug the first time. The parts manager re ordered it this time.