@zonefive

Looking at your signature it seems like you're maybe taking your issues to the wrong people.

Like Caryalon said, there is nothing magical or special about these transmissions. The exact same transmission is used by other manufacturers like Porsche and Audi so this isn't even a BMW thing.

If you ask me replacing the torque converter is a MUST if you want a fully rebuilt transmission. There's a shop I've heard good things about that specializes in rebuilt and upgraded torque converters for these transmissions...but of course I can't seem to find the link for it anywhere. (I'll try to find it and update this)

If you plan to keep the car and want reliability then forget about the junkyard route. You're guaranteed to be playing a guessing game even if you pull a trans that works fine, you never know how long it will last.

Pay the extra and get a fully rebuilt unit with a warranty.

There's a shop in Toronto that I'm familiar with that does work for all the German dealers in the city and they charge about $3500 for a fully rebuilt transmission out the door with a warranty just to give you an idea of what it "should" cost give or take.