Not to be a Debbie Downer, but I had the Dinan intake, throttle body and stage three software. Stock ZHP exhaust. I remember driving away after having all that done and thinking "this is it?". Dyno numbers were pretty dismal too. Didn't notice much difference after getting a cat back Corsa TSE3 exhaust.
For me it wasn't worth the expense. Put a set of headers on it instead along with a basic tune. You'll get much more bang for you buck, even with the stock ZHP exhaust...
Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
H&R sport springs, UUC sway bars, BMW Perf. Rotors, UUC SS brake lines, Hawk HPS pads, CSL replica wheels,
Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers