Was looking at that but thought that I’d wait for one where I can fit a proper CSL filter (inside the box) rather than none or a cone filter on the snorkel.
You also have to be careful where the breather & IAT sensor goes as the Z4 has less clearance to play with then the M3.
You’ve also got to remember that you’ll need a different map (and not just one possibly included in a sale) as the M3 and Z4M don’t have the same ECU (MSS54 vs MSS70)