I've found out myself...
the left piece was orignally placed at the left front from the car: behind the left grille just near left front 'pinker' and suckin' air to some radiotor in the front left corner.
The most right piece and biggest piece was place at the lower right corner (front) of the car, suckin' air from under the car (that flap) and a second channel from near the righ front grille ( near right front 'pinker'. This hole box with this two air-vents was delivering cold air to the intercooler??
I'm I right, it's the intercooler place at the lower right??
This is wat bother's me most. If they changed the whole box just a little: took a piece away, they could re-assemble it with the j12 bumper. Bust they throw it just all away.
I think I can feel i've just a little less power...
The car seems less brutal when you pulling up pedal to the metal!
Anyhow I've replaced a piece of the box with that 'flap' so it can take again a little more air from under.
Gladly I've got an extra airvent now with the new bumper that directly comes out on the intercooler(?).
The worst could be that the cold air isn't isolated anymore from the hot...
That's all for now,
I'm drooling... frown