In my opinion, you'd be defeating the purpose of the K&N, which is to decrease the restriction in the airflow, because the additional paper filter would add to the air flow restriction, and you'd be adding to the paper filter's filtering quality an unnecessary additional filtering from the K&N. I won't go into whether or not the K&N does an adequate job of filtering, other to say that I think that it does and use them on my two vehicles.
