This has been an ongoing discussion for years in all sorts of Porsche forums. While the IPD has looked like it might work (the wedge, not the dimples) I have always held that if it was that quick and easy Porsche would have done it. This is all on a stock motor, but I'd be willing to wager that, aside from adapting a larger GT3 tb if you really are moving more air, IPDs do next to nothing regardless of the state of tune. The K&N filter element actually surprised me - I would have guessed it would provide barely noticeable increases, but I will stick to no MAF issues over the very slight increase it provides.