After getting my APR stage 1, it was recommended that I install a K&N drop in filter. Although air filters should be changed regularly, and should be common knowledge, I know that many people do not know where to find theirs - someone may find the air cabin filter first (they look similar). Anyway, for 50 bucks I decided to do it. Here its is

SUPPLIES - All you need is a phillips head screw driver and K&N part number 33-2209

The air filter is located behind your passenger side headlight, below the ducting shown in the picture to the left. To get at the air box, you will have to remove these two plastic parts. The process is very straight forward and easy. Towards the front of the car, you will see that this part is only held in by 2 phillips head screws. Simply unscrew these screws and then separate the two pieces at the middle -as pictured below. After they are separated you can just pull them both out of the car.

In the picture to the left is the air box. You will have to open it up to get to the air filter. There are two phillips head screws holding it in place, you will have to remove these screws and disconnects a hose or two to get enough room to get the filter out. See below.

After you disconnect the appropriate things, you will be able to lift the cover of the air box enough to pull the old filter out and insert the new one. It took me a little bit of time to get the new one to align properly, but was not a big deal. See below

Close up the assembly in the reverse order.

Good Luck!