Anyone know of a vendor that sells the replacement filters for the HKS RS kit?

 

Try Boost Solutions give them a call they can hook you up.
(770) 904-2644

 

you can get them directly from hks at hksusa.com. they are $25 each now that HKS raised their prices The HKS RS intaker uses the bigger ones (200mm). They have several colors. I think Z1 has a 5pack deal also.