In order of install: K&N air filter removed air silencer @ same time: replaced paper air filter with approx. 15k the car and it seemed to rev faster, especially in upper rpms and gave a nice air intake noise from under the hood. Steeda Tri Ax: Excellent shifter. Shorter throws, wrapped electrical tape around the base shifter between the upper handle to eliminate transmission noise that was directly being generated after install. The tape works great. Bassani X with cats: My favorite mod as it not only did it noticibly increase hp&tq, but made a nice sounding stock stang into something of beauty (to my ears anyway). Louder than stock, but certainly not loud. Not drone with stock catback. Bullitt suspension kit (includes springs/shocks/struts): My second favorite mod as it transformed my stang from a softly sprung, pretender into a real handler. I never liked the stock variable rate springs, because it initially was too soft, upon further compression then would hold up. The Bullitt kit is specific rate springs with tokico OEM shocks/struts. No more brake dive, handles much better with no more leaning in the corners. I wish it would have dropped further in front by another 1/4" or so, but other than that, happy with the kit. Maybe I'd go with Steeda next time as the specs are right on with the Bullitt, but with more front drop. Densecharger TB tube: Gets rid of the stock waffle tube underhood improving looks, with the stock three turns and replaces it with a single turn into the MAF. Performance wise, felt better throttle response similiar to adding the K&N and similiar intake noise improvement as well. Wheel Adapters for the rear: These are AIM 1.25" wheel adapters - not just spacers as they come with thier own lugs. You properly torque them down on to your hub and then bolt your rims to it. I can highly recommended these if your staying with the stock rims. Brings the rear wheels flush with the fender even with stock sized tires, gettiing rid of the pinched in look of a stock SN95. Added bonus of percieved better handling with a wider rear track. '02 PI cams: Felt a similiar gain to the X-pipe, but install was for me approx. 15 hours over a weekend was much longer than the x pipe - a 2 hour job. Not a trivial installation, but worth the effort. End of all this my car dyno'd at SAE corrected 218 hp / 281 tq.