[tpscruiser]

Expresso,
Sorry , but I don't have pics on a hosting site to link here.
I just did almost the same thing to our second PT today.
If you measure the inside diameter of the OEM plastic part that goes into the fender opening, you will find the diameter is smaller than the throttle body bore, therefore it's restrictive. What I did was take a 2" PVC Long 90 degree elbow. One end I cut off the part that flares out to accept a 2" pipe. The other end I opened the inside diameter to 2 1/2" using a 2 1/2" hole saw in a drill press. It's a little tricky getting started but take your time and it will come out fine.
The 2 1/2" opening allows the elbow to fit over the nipple sticking out of the air box. The LONG PVC Elbow then lines up with the hole in the fender. I painted the elbow Satin Black and used a sheet metal screw to hold it in position on the air box after drilling a pilot hole for the screw. A LongPVC elbow was $.94 at Home Depot.