Buy a standard pipercross or K&N induction kit, some appropriate piping (I used a 30cm aluminium pipe from the filter and then a flexi-fabric pipe from the filter to the airbox), some revotec hose reducers to seal the pipe together, some jubilee/ worm gear clamps and a hose reducer (from whatever diameter down to the lowest diameter pipe possible, so about 38mm) and you're good to go