wiring harness
David, when I upgraded to an AIWA MP3 from Crutchfield, they give you a free wiring harness/adapter. Naturally, NSX wasn't listed in their catalog of stuff, so I took a chance and specified Acura Legend, and it fit fine and the wiring corresponded. You're safe with that, unless Acura changed their wiring in the meantime. Very likely, if you specify a Legend that is the same year as your NSX, you'll be fine...
Hope that helps!
Don Davis
Heidelberg, Germany
'91 Black on Black