My airbox lid after 50K miles of K&N horror.The radial marks are from the molding process.EGR and PCV are probably both much greater particulate sources.
Information shared just the same. I think WIX does a good job with their oil filters. If you see them cut apart along with others they have some of the nicer features. Going to sponge wrap the filter and oil it? Just so you have the chance to do that as you now won't be putting on a K&N. LOL..
After starting this thread, I feel a bit guilty - as I`m not using one. This will be the air filter I`m using http://fmsfilters.com/products/air-filters/46277 Will be making an box to house it ( in my Mk1 Jetta 1.6td) - am thinking 8 inch Plastic pipe, or roll some stainless or maybe galvanized sheet metal.They are about $12 per.
You're right - ***! The prelude filter runs 135 cm, While the 1.6td is 215(ish) cfm.Damn you INternets....