With stock DP you will be fine. It will be slightly louder than your axelback only set up and hold much of the same tone. Adding some catless DP you will alter tone more radically and have a real increase in sound.
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08 AW 135i | Cobb | ETS FMIC | ER CP w/ Tial Bov | AR Catted Downpipes | Berk Mids | Meisterschaft GT SUS 1M |M3 Control Arms | M3 Sways | M3 Rear Subframe Bushings | Wavetrac LSD | AST 4200 DA Coilovers | HRE R43 | Hankook R-S3 |Full BMW Performance Interior | Revozport 1M Raze Aero Package in Satin Carbon |1M Body Conversion|