The previous owner of my M Coupe had installed most of the Dinan bells and whistles, most of which I have removed. One I kept was the cold air intake (CAI) as it is one of the few out there for the S54 in the Z3 chassis and has positive reviews. While I had the front bumper off, I took the opportunity to remove the filter (it’s buried deep inside the driver’s side corner of the bumper.) Good thing I did, as all the filter oil had long since dried up and the filter wasn’t in great shape. There’s simply not enough room for it, the result was several dents in the wire mesh. So I started looking for a slightly smaller replacement. The Dinan filter is a wire mesh and cotton gauze type filter, virtually identical to the K&N filter. I came up empty looking at K&N, AEM, and AFE. But Amsoil had a filter that looked like it would fit the bill, model EAAU3555-EA. Their filters use a “dry” element with no oil, but are reusable and can be washed. Though this filter was slightly smaller than the Dinan, it did have an inverted cone filter top, so chances are it’ll flow just as well if not better.
With the new filter installed, I saw there was a bit of interference with the aluminum crash bar. The Dinan filter probably hit here as well, but it has a rubber top unlike the Amsoil’s metal. Since I didn’t want to worry with the two metal pieces rattling, I did some clearancing on the crash bar.