Stock Air box cone filter?

[E39TOF10]

Has anyone removed the stock charcoal filter and attatched a cone type filter?
From what I can see, there is a pipe that extends inside the stock box that a cone filter could be attatched to. cant seem to find the size of the tube. Was thinking a dinan replacement cone filter might just work as they use the top portion of the stock box. Im sure someone has tried this. Of course Dinan will not give up the opening size use in their replacement filter for the Dinan carbon fiber intake system.

[ur20v]

I purchased a used set of OEM airboxes ad cut the OEM airbox tube off and used silcone hose and alloy tube to make it all work. With this setup you can run BMC, Ramair or K&N etc of the right size..