I have Evolve CSL airbox installed with Alpha N tune. What I noticed is the acceleration is more responsive. HP gain is there if you have a Euro setup on the exhaust side. The installed is not complicated but we do need to modified a few things for NA Z4Ms. There are few have SES 2FDA fault code. Evolve provided a final flash to turn that off. I wasn't happy with the workaround but it is difficult for a company to figure out why few have issue out of many using the same software. I finally fixed the 2FDA fault this passed weekend but need more seat time to confirm.
PCV hose need, the larger hose on top, needs modification. The one Evolve supplied is not the same. OEM hose is not long enough to reach the airbox fitting.
Here is a better picture of the connection.
We need to splice MAF to use IAT.
Overall, I am very happy with this mod. The intake is very distinct.