I just changed the fluid in my 08 E4 a couple weeks ago. I have to be honest and say I did not measure the amount removed or the amount added. I used a power oil extraction pump (we use on our boat) to pull as much oil as possible out from the rubber drain/fill hole, then refilled until it ran out the same hole.
I must say it did not seem like it was 12oz, it seemed less but again I have not real idea.
Well that was about worthless info now that I typed it…