Why not just go with a high flow drop-in filter (un-oiled of course)? Much cheaper, used the stock setup, and I've read that you can still get some of that "woosh" noise everyone wants.
2011 E90 335i LCI // Jet Black / Beige Dakota Leather / Double-VANOS/ Premium / Sport
Mods // Cobb Stage 2+ Aggressive / ER Charge Pipe / AR 4" Down Pipe / AA FMIC / LUX H8 v3 Angel Eyes / HPB Interior LEDs / Wavetrac LSD
Other // Shell Rotella T6 5w40 / 18" APEX EC-7 Wheels (9" Front|9.5" Rear)