+ 1 on the intake question (for 335). They can't claim it "doesn't help and the stock one is fine" when we've all seen the dyno numbers. Perhaps bone stock it doesn't help much, but they are smoking something if they think a car with the BMW Performance Tune/Package will not gain HP with an intake.
MANY people, like me, would likely jump at a (somewhat) reasonably priced, factory warranty intake that doesn't have to be yanked before dealer visits, etc. Exactly the reason why I, and plenty of others, paid the premium for the BMW Perf Exhaust.