Ok, this is what I did to my 08 S, on the account that only one company makes one for this model (That I could find) and its $250...plus I wanted to keep a stock look and not flash my chrome CAI all over the place. It costs about $40 for me (didnt get a K&N, $75 or so if you go with K&N). First off, heres what you need...
1. Several feet of 2'' ABS Pipe (Home Depot) *Melting temp of around 230F...no worries as long as its not touching engine or radiator, which it doesnt in my setup.
2. (2) 90 Degree joints (Home Depot)
3. (1) 2'' to 4'' adaptor (varies with air filter selection)
4. Appropiate Glue..
5. Something to cut the pipe with.
6. White out (yes you need it...)
7. Tools (duh)
8. Air Filter (duh)
Ok here we go...first you need to pop the hood and pull out that crudy stock intake.
To do this..you need to unscrew the fusebox and take out the battery...
Now take the air filter out of the air box and remove the nuts inside it to lift it out of place. (Dont have to completely remove it) Remove the stock intake.
Now we need to locate our hole where we can get cold air, this can be found just behind the headlight and can easily be seen with the stock intake removed.
Now its time to get under your car...hopefully you dont have it lowered or you wont fit (I barely can get my head under). Once under look infront of the left wheel, there is a plastic wheel well cover, we need to get this out of the way. Luckily its flexible so it doesnt need to be completely removed. Locate the bolts shown and remove the one plastic clip. Then Pull down and to the right of the car and it should slide out enough for you to see inside.
Now you need to cut the pipe to fit...my dimensions are below, yours may be different, check to see and always cut a little longer than you think you need.
The filter is going to go like this in the car...
Check your angles, slide peices together and check the fit...if its good CAREFULLY remove the intake and use white out to mark the angles for the peices. NOTE: For me, the only way to get it in position was to insert it from UNDER the car.
Well if it looks like it fits DONT GLUE IT YET. First attach the expansion pipe as well and put the intake in place, then attach your air filter to make sure your have enough clearance to put the wheel panel back on.
Hold your breath and glue the peices together. Check the fit again and if you did it right, it should still fit. Put the fliter on, and go topside. Slide the 90* pipe into the stock air box (I had to sand the pipe a little to get a good snug fit) If it fits, mount the airbox. I also drilled a little hole in the intake tube and the airbox to put a screw through to hold it snug. Press the intake into the air box and go back under the car.
Now put the air filter on and replace the wheel guard, be sure to slide it into the "slot" on the side. Did it work?
Mount the fuse box, put the battery in and take a look...
Finally...fire it up
, I noticed a slight difference in sound though not as deep as it could be due to the pipe diameter.
* You could route your custom CAI right from the intake hose, if you used large enough pipe, and drilled a hole for the MAF. This would require complete removal of the aair box of course.
* Feel free to make this out of metal pipe if you wish (autozone has the stuff) Just mark it and weld it yourself if you can, or take it to a shop to have it done for you.
Hope you enjoyed this, if I left anything out, let me know.
I am also currently doing custom under dash LED neons for a friend, if anyone is interested, I can post a tutorial for those too
Congrats on your new custom CAI