I saw a few cars using ITG filters but can't find a part number for ITG filter for 04-06 R1 (5VY).

Anyone has a link?

Moti

You will struggle to find a filter base plate to fit directly to the throttle bodies due to the fuel rail being higher than the top of the throttle bodies and the servo motor infront.
You need to make a base to raise the filter above the fuel rail.

Have a look at this thread for more info.
http://www.locostbuilders.co.uk/viewthread.php?tid=87792

[Edited on 10/2/09 by stuart_g]
Rescued attachment Air filter base plate.JPG