don't know if it's worth it
I have a drop in k&n in my 04 camry 4 cyl. It pepped it up a bit. I really can't tell if the throttle body spacer is doing anything. The car definitely doesn't seem slower but I really can't tell if it made any improvement in performance. Gas mileage hovers right around 27 MPG so no real improvement there either. I read that you get the most benefit if you have the k&n cold air intake system on the car (which k&n says adds about 14 ponies to the ranch) plus the throttle body spacer.