I've got a proper
Join Date: Oct 2008
Location: United Kingdom
There are slight differences in the boxes, the way the airfilter is clamped down and the text on the lid. They are all interchangeble though.
Strictly speaking if you have an Alfasud then you should get one with a lid that doesn't have ALFA ROMEO pressed into it. It should be smooth and the writing printed on in white. A local printing company created a template for me to respray all the writing onto the lid of mine, I can give anyone who's interested the contact details.
You can get a K&N panel filter to go in the box. You might also need to get a length of silicon hose for cold air intake, a section with a 135deg bend trimmed down fits in quite nicely.
I think they look a lot better with a nice freshly painted box than seperate filters. The only downside is you loose some induction noise.