I put a K&N on my SE and I noticed a huge difference. Throttle response was better and at, um, highway speeds the car simply breathed easier.

Course, that may be less the K&N then the sand and twigs I had to vaccum out of my airbox...

Scott
96 SE, MTX, BAT 22mm rear anti-sway bar, BAT springs and Spax struts
96 Caprice, 9C1
Rayon is made of wood!!!