I run the same wheel setup as you. I have added Eibach Pro Spacers. 12mm on the front and 15 mm on the back. Works good and looks amazing. Don't by cheap spacers. They will warp. You need quality metal. Eibach is right at the top of the list.
2011 335i M-Sport Sedan | MHD Custom Tune by Wedge Performance | ER CP | Catless DP | Koni Sport Dampers l Eibach Pro Kit Springs | M3 Suspension Upgrade l BMW Performance Exhaust | BMW Performance Front Grill | OEM Euro M-Sport | 19" Volk Forged Performance ME's | JL Audio HD 900 | Morel Hybrid Components | JL Audio W3v3