We do a Performance intake for the 330d:
http://shop.speedreligion.net/air-intake-93-c.asp
It is not possible to fit a 'normal' cold air intake like some cars as the 330d's air filter sits along the whole side of the engine and only draws air though the large enough sized 'snorkel' from the grille area...
We have tried a whole range of air intakes for the 330d and find the K&N to produce the best benefits at a very cost effective price.
We have them in stock and are available for next day delivery if ordered through the website.
Have a look around, 330d's are our speciality and not many other people know them inside and out like us...
Anthony.