Ok, its not anything big like headers or exhaust, but it is something. Just bought and installed Bosch Icons, Silverstar Hi/Lows, and K&N replacement filter. The filter need to be replaced badly though, it was clogged with pollen, most of the filter was yellow. Although with the new K&N filter it does seem to have louder growl at around 2k RPM's. Not sure if its just me but it does seem to sound differently.