[vasillalov]

I just did some digging in realoem.com. Here is some interesting stuff:

Z4 35is front disk: 34116782593
Z4 35is front disk Dimensions: 348x30
Price: $170.83

Z4 35is rear disk: 34216782607
Z4 35is rear disk dimensions: 324x20
Price: $96.42

335i Front disk: 34116770729 - Up to 04/2001
335i Front Disk: 34116855000
335i Front Disk Dimensions: 348x30
Price: $138.22

335i Rear Disk: 34216764655 - Up to 05/2001
335i Rear Disk: 34216855004 -
335i Rear Disk Dimensions: 336x22
Price: $102.94

So basically, we can upgrade the front disks from Z4 35is for around $33! Cool!

...and there is actually no point of using the rear disks from Z4 35is since they are actually smaller!