The other reason the idea might not seem so clever is this. Let's say you get pulled over for some other citation. The cop thinks your plate says NSX and he runs it through. He (or she) finds that the owner info doesn't match your driver's license, and thinks the car is stolen (or notices that the plates are different, and sees what you've done). He may not cite you for the plate thing, but he could become a lot less lenient on the citation for which he pulled you over.
My suggestion - think of some way you could have a unique plate without going upside down. Remember, the reason NSX is taken is that there are probably a few hundred NSXs in your state, so there are a lot of folks who might have asked for it. But do something more specific - like NIX NSX (my personal favorite if my name were yours), NICK NSX, TRBO NSX, 99 NSX, etc - and your chances of getting that plate become much better. And there are always the old standbys like NSXTASY, NSXOTIC, NSXTREME, NSXLENT, etc.