I have the 328i coupe with the sport package and it's got a six speed auto by ZF. Says it on the transmission. I just replaced the Mechatronic sleeve. I don't know if the GM trans has that but I know the ZF does.
I'd be happy to learn that I was wrong so that I could buy some cheap fluid and replace it about three times to make sure I got all of the SP out. The sticker on the side says ZF fluids only.