Air Filters & Induction Kits
An aftermarket air filter or induction kit is one of the first things people tend to add when modifying their vehicle. Be it for normal road use, or for track. Most OEM intake systems are fairly restrictive, not to mention a bit boringly quiet. So to get yourself a pretty cool induction noise (especially on turbocharged cars) and potentially even get a small increase in performance, this is definitely a good starting point.