And they are assembled at a plant built just to hand-build NSX's.

The Supra is NOT an exotic.
The Corvette is NOT an exotic, it's just an ordinary car with extraordinary performance.
The Viper sort-of is (it involves some more extraordinary technology than the vette does--its steel space frame comes to mind).
The NSX is definitely an exotic.

don't get me wrong. I like all of the cars I just mentioned. None of them really equal the NSX in the technology department, the NSX is just ancient now and definitely no longer competitive in the sports car arena. The Corvette has undergone 2 major revisions since then, The 911 has undergone 3 (993, 996, 997).