It looks like Downforce is developing one to be available next year.
http://www.downforce.biz/nsx/
http://www.downforce.biz/nsx/nsxhsc.htm
Interesting... they also have $700 Type R rear spoilers.
http://www.downforce.biz/nsx/
http://www.downforce.biz/nsx/nsxhsc.htm
Interesting... they also have $700 Type R rear spoilers.