here's some mods i've done...3" airbox mod. simply remove the airbox, cut out the thin black pipe, and replace it with a 3" PVC pipe. preferably a thin walled pipe so it fits easier.you can then cut off some length at the end and add a 3" 4" adapter making a bell mouth for even more airflow.my new saab sport exhaust:compared to the old one, it's a lot lighter, and less restrictive.next is the SAS rear sway bar. a lot stiffer, thicker, and heavier than the old one.a new hyperboost diverter valve. it's quite the hunk of metal compared to the old cheesy plastic stock one.