I have a K&N drop in. Cost like 40 or 50 bucks from Autozone. I had the intake kits on my last two trucks. But for what I'm using this tacoma for the drop in is all I need. If you've ever gone into a shop and tried out the K&N display it is bad ass and shows exactly what you are getting. The display uses a stock filter and the K&N filter and pumps air from the bottom. There is a ping pong ball that moves up and down the tube depending on how much air gets through the filters. The stock filter, the ball doesn't move at all. The K&N filter the ball shoots to the top of the tube. So the K&N filter is a better choice than stock. As long as you know that the amount of air pulled into the vehicle is controlled by the vehicles computer.
I have run the K&N filter on all of my vehicles since 1990 with no troubles. Every vehicle I installed the filter in I heard from the 'experts' that it was going to ruin the engine by letting particles get past and wear the rings and cylinders causing oil burning and that it would ruin the sensors in the intake tract for the fuel injection. 5 vehicles, no oil burning, no problems with the sensors in the intake tract. I must be doing something wrong.
I have even used a K&N on my Husqvarna commercial mower since 1996. No oil burning and the secondary filter stays as clean as new, something the OE primary dry filter never could do.