Car airfilters come in all shapes and sizes and cost anything from £20 to £200 for a full induction kit. The airfilter is an important part of a vehicles air intake system becuase it cleans the air before sending it through the rest of the car. By doing this it means you dont have to worry about things like dust, mould and pollen etc. geting into your engine. Performance enhancing air filters are popular amongst car enthusiasts and boy racers. This clip shows you the difference in sound when adding a simple air filter to your car.