Edit: After some suggestions in this thread i got larger diameter piping and have updated the DIY accordingly... enjoy
this is a simple modification, that only cost about $12, took roughly 25 minutes total, and that i hope will redirect some outside air into the stock airbox, which i believe is best for these cars.
Here is all that you need, PVC conduit elbow 1-1/4'', pvc 45 degree elbow connector, 2x2 plastic flashing. (flashing was on the top shelf above the pvc fittings at Ace)
conduit elbow (pvc)
45 degree connector for 1-1/4'' pvc
before I left the store, I made sure everything fit. the fitting fits on the end of the pipe, and should fit snuggly in the rubber seal on the flashing.
first i turned the wheel all the way to the right, and removed the wheel liner, like you would do if you were changing the bulbs in the driver's side headlight
under the stock airbox, is a resonator bottle that looks like this
it goes in here...
i used an 8mm wrench to remove the two bolts holding it on, and pulled it down, to dislodge it from the airbox. it should look like the above pic when out.
after that i pulled the big piece of foam out a few inches, so see where it was connected..
it's held in by that big black plastic square, which is held on by two easy clips, one was fairly obvious, and easy to reach.
the other i had to reach through the lower part of the front grille with a screwdriver,
i broke my foam taking it out, but what the heck. i can get more foam.
next, I fit the plastic flashing piece against the front (lower) grille, so that air will trap in there. I was able to secure mine by putting the top flap between the plastic box piece (that sits above the foam), and the grille.
insert it like that^, then bend the flap nearest you on top and pull it through the bend of the box, and pull the whole piece toward you to line up with the pipe... this should wedge it and secure it real tight...
you'll know what i mean when you get under there...
the 45 degree elbow is to make the required bend to reach the flashing. i had to size it up before determining the proper way it should face before tightening it on.
after i decided which way to face the connector, i tightened it on the pipe, and pushed it through the rubber seal on the flashing almost all the way through, still with the pipe turned sideways like so...
then i turned it upward to reach the airbox hole.
I wanted to try and make sure and push the pipe through enough so that when i inserted the other end into the airbox, it pulled back out a little from the flashing... this way the rubber seal goes inward toward the pipe, creating more of a funnel effect. the bare end of the pvc pipe should fit very snugly into the hole on the bottom of the airbox, though you may need to wrap it with some tape or something... it should go all the way up into the airbox like so.
... it should all be very nice and tight, but of course that's what she
Coupe fitment pic courtesy MikeGrote (See post #70)
disclaimer: i am not responsible for anything you do to your own car, nor is this description of what i did, in any way, an encouragement to do, or endorsement of what i did. i'm simply telling a story.