There are a few options for the air intake. It is up to personal preference, but in general it’s known that maintaining a nice aesthetic view is preferable. Therefore, it is imperative that the stock intake is used.
29.2.1 126.96.36.199 TOOLS REQUIRED
188.8.131.52 TIME & $$ .3Hrs & $20
I had a cold air intake, but since I went turbo, I have this old cold air intake shortened specific for E30M30. It’s not K&N, but it worked fine.
It’s preferred that you use the factory intake as indicated below. This intake from any stock E28,E23,E24,E32,E34 airbox. The E32,E34 boxes are much more eye pleasing, however any of them will work. They look like this in Figure 82: