[TheSiege]

I'm hoping some experts can check my thinking on this wheel/tire fit question. I'd like to confirm if I can put 764M wheels (fronts are 9 wide) on my 23 M40i. I have read everything that I can find (and dealers are useless) and I see a few people with earlier years saying this works. Still, when I look inside the wheel- I don't get how they fit.

I have 887M 7.5x19, with the AS 245/40 tires. According to the width/offset math, the 764 (9x20) will be 15.1mm closer to the strut. See picture below in green, but there is not 15.1 mm of extra space.

Thinking about this more- tools like Willtheyfit.com assume tire sidewalls are straight - no load/bowing. Looking at the bulge in the sidewall (red) this is clearly closer to the suspension than the rim itself, and presumably the lower profile 20's would NOT have this much outward bow? Still, the inside wheel rim moving 15mm closer seems tight....
Is that how 20x9s fit? If they do they at all?

If anyone has photos of a 22/23 M40i with these wheels, it would be VERY appreciated.
Thanks for the help!