All of these items came off of my 1999 Boxster (now traded away)
Zucs Powerflow air intake, comes with plenum, couplers, clamps, K&N Conical filter, this was $400 new.
If you have the tools and want to tinker with your car for enhance engine sound and intake noise, you might like this. Keep your OEM airbox if you want to swap back. The so-called increase in HP is very debatable though. You will just need to clean/re-oil it with the K&N recharge kit. Instructions in the photo album below along with pictures of the installed unit. Since this is an older design, I'm asking $80
New in original box Hengst Stock Air filter Boxster 986 1997 - 2004
You know you're going to need one anyway and if you come over, might as well buy this too. Asking $10
K&N Air filter for stock airbox, Boxster 986 1997-2004
Sells for $49 at partsgeek.com (
1997-2004 Porsche Boxster Air Filter - Air Intake - K&N 97-04 Boxster Air Filter - 131-03018162 - PartsGeek), If you want to experiment with intake noise, this is an easy modification. You will just need to re-oil it with the K&N recharge kit. Asking $25
Photo album here:
https://goo.gl/photos/2Sd3hWk4fzkQZN7a7