I'd have a word with Tony Lewis who works out of Berry BMW Heathrow. He hasn't updated the m5 offer on the babybmw forum but he probably would if asked see:
https://babybmw.net/forum/viewtopic.php?f=80&t=120054
Also see coast2coastcars.com
Drivethedeal sometimes do BMW, I ordered the wife's 220AT through them.