I have just purchased a 2000 INSERT INTO post VALUES (W) GALANT 2.5 V6 SPORT and have been looking for some basic mods, one of which is an air induction kit.
Having trawled the internet the only thing that I can find is a replacement air filter, however with a little help from a friend I came across 'Power and Performance' at Honingham, nr Norwich in Norfolk. This company will manufacture an air induction kit to fit your car if no off-the-shelf parts are available.
Having spoken with Mike at Performance Parts, he suggests that an air induction kit is not necessary. He said that the standard air box for the Galant V6 is a good size with a large surface area for the filter. A replacement panel filter from someone like K&N would suffice, and could be improved by cutting some holes in the bottom of the airbox.
I have a K&N replacement filter on order so I will give you more details when this arrives. Hope this helps.