Completed this mod today on the 1.8l. There is additional piece on the intake (a resonator box) at the curve in the stock composite intake tube. Just removed this piece.
the pic below shows how I attached the flex tube to run out of the inbox, I had to grind off 2 tabs to get it to seal.
IMAG0009 by
v3n7o, on Flickr
On the back of the fog-light blank I attached an intake adaptor held on by two stainless bolts (the nuts have the teflon inserts so they wont back out) then sealed with black silicone.
IMAG0011 by
v3n7o, on Flickr
I used a dremel on low speed with a roto-zip style bit to grind out the ports on the fake grilles on the fog lamp blanks.
IMAG0018 by
v3n7o, on Flickr
Finally I re-assembled the bumper and connected the tube by putting the fog light back in last, I accessed the tube through the wheel well to position it correctly. (I will probably paint the screws black ot match the rest of the trim)
IMAG0019 by
v3n7o, on Flickr
I didnt add any additional anti-siphon, there are two small holes at the bottom of the airfilter box, one at the entrance and one at the lowest point, I did increase the size one at the lowest point slightly with a small file.
We had a rainstorm last night so I took the sonic out for a drive (I had to clear 2 codes because I first forgot to plug the MAF back in, then forgot to re-attach the temp sensor in the bumper...)
I purposely tailgated people, drove through puddles, and ran on wet freeway in a nice steady rain between 70-90MPH. Then drove another 15 or 20 mins back home. I pulled the airfilter out and was pleased to find it was bone dry. There was some water on the front of the fog lamp area, but most of the intake tube was also dry, no water had made it up past the first bend.
Great success.