Sorry to hear about it, Dave. It sounds like someone in your area either (a) doesn't like you, or (b) really resents your car, enough to vandalize it. It's probably (b)... the only reason I mention (a) is that one of our members here had his NSX repeatedly vandalized by a vengeful ex-wife.
I would suggest you think short-term and long-term. Short-term, you should (1) call the police immediately to file a police report; (2) call your insurance company next; and (3) call the body shop (presumably the one who did your previous repair, assuming you're happy with their work) and get their advice on what to do with the car, such as hosing it off (?) and getting it to their premises and away from its current location.
Then you can think medium-term - what to do for transportation while the car is being repaired, and where you will keep it once the car is back.
Unfortunately, on a long-term basis, assuming they don't catch the cretin who did this, there's a good possibility he might try it again after it's fixed. The alternatives mentioned by others - getting a beater and keeping the NSX in a storage facility, or moving somewhere the car will be safe - may be the only way to keep your NSX safe. Otherwise, you may be forced to choose between risking a recurrence or selling the car. I don't need to say it, but the whole thing sucks. All it takes is one person to make life miserable and screwed up, and you happen to have such a person near you with a hard-on for your car.
[This message has been edited by nsxtasy (edited 27 February 2003).]