Great thread, I did mine last night using black filters and it looks great, and with only $60 spent!!!
I would add 2" PVC pipe has to be cut to 2 inches for the front intake tube, and 5 inches for the back pipe. I played around a bit with different lengths and these seem to have worked best. Clean those inside and out to ensure no shavings are left in. Will post pics later.
2011 e92 335is DCT - Cobb, ETS IC, AFE DCI, BMW PS kit, M3 control arms, various cosmetic improvements
2006 e90 330i 132k miles SOLD!