Its funny I came across this thread tonight. I was just gonna post these photos in a new thread. When we had our 1er forum and 1addicts meeting at the Ring two weeks ago... one of the 1er forum guys there with a 135i - had made his own Mr. 5 intake. He used common plumbing pipes from his local German hardware store. He painted the pipes in stealth flat back. He said it really did make more power. How much is anyones guess. He also said he had a flash tune and I think a bigger intercooler(?) pushing close to 400 PS.
Here are some pics of his car...
Also on an side note... My tuner (MS Tuning, ie Marcel) told me that the bext CAI is the one from Alpina. But they won't sell you one. The only way they will sell you one for a B3 (?) is IF you provide them with the car's German registration papers, plus a photo of the damage broken part. THEN they will let you order a new CAI box. lol
Dackel
PS: I found this link with photos on the copy-cat Mr.5 intake on an e90 335i.
http://www.google.de/imgres?imgurl=h...1&tx=109&ty=60