are APS the only people to make a cold air induction kit for a 99/00 year impreza or do other people make them

 

Plenty of peeps make induction kits. IIRC APS are the only people who make the type that puts the filter in the space under the wing rather than in the engine bay.

Or rather I have seen others advertised in places that I don't recall but they were all essentially unbranded.