This should probably be in the engine section but K&N make a filter that replaces the bottom half of the k-jet airbox, popular opinion is that all it does is make more noise & suck hot air from the engine bay which is counter productive. Better option might be to make your own by simply routing some ducting from behind the grille into a hole in your airbox EDIT: Sorry its Pipercross not K&N- http://www.easier.com/64074-pipercross-vw-golf-k-jet-induction-kit.html