I have the GruppeM intake, as well as the Tubi Rumore exhaust. WOT sounds ridiculous from the intake, although performance gains are fairly minimal. Some people have reported 10hp increases, and others 2hp, so it is more for looks under hood and sound.
I love the exhaust, as it sounds exotic and unique to the car. I'd say more like a Maserati GT than a Mustang. Plus, it's made across the street from the Ferrari factory, so I was sold.
2009 e92 M3 Individual Laguna Seca Blue
|Black Novillo|DCT|19"rims|Carbon Leather|Premium|Tech.|Heated Seats|Prem. Sound|iPod|
Mods: |Electronic Performance Steering Wheel|ZCP CF Spoiler|ZCP CF Spliters|ZCP CF Mirrors|Edition Front Grilles|Edition Side Grilles|BMW Performance Brake Handle|3D Design Pedals| Style Rumore Exhaust|H&R Springs|LCI Tails|Challenge CF Door Panels|