I think a drop in filter could help I have read in other threads that in our cars the intake is efficient. the tune will give you the most gains. Good run.
BMW 135i Jet Black AT. Hpf intercooler, Hpf exhaust, injen intake, ER competition oil coolers, ER charge pipe, Tial BOV, AR catless DP,BMS OCC, VMR 718s 19s, BMW performance spoiler, agency power rear diffuser, slek lip (on highway somewhere), FXomar abs lip, Ohlins Suspension, All M3 bits, Cobb protuned, turner 3 clutch LSD, Escort 9500ci