I'm running 19x10 AG ZCP on Square 275/30. On KW sleeves with a bout a finger gap in the rear I was able to running 15mm spacer with 0 rubbing. Fronts I had to run a 5mm spacer and had to shave a very small piece of the of the spring height adjuster. Fronts were on full low and had 0 rubbing.
Final ET were 15mm front and 5mm rear.
E90 M3 AW/Extended FR•Ohlins•Borla•ACM•K&N•IND•BBS•Vredestein•Velos Designworks•Vorsteiner•BMW Performance•Lux AE•Arkym