This is an NSX-R style diffuser which mounts over the top of the factory 1991-2001 rear valance, and makes the car look like the 2002+ NSX-R diffuser.
The part is FRP, intended to be painted - this is authentic Garage Kite, imported from Japan (and it's new!) - $200
The part is FRP, intended to be painted - this is authentic Garage Kite, imported from Japan (and it's new!) - $200
