I agree with the majority of posters on here-- save the car cover for secure areas only as it likely invites vandalism. I routinely use my OEM car cover, but only for protection from the sun, bird dung, tree pitch, etc while at work and at friend's homes and never to hide the car from the public.
Shorty after getting my car, I naively parked my new baby right in front of a busy bar (at night) and placed the car cover on it. When I returned I found the car cover torn off and beer poored all over the rear of the vehicle!
I really do believe many people view the way we treat our cars as almost an excessive compulsive form of behavior and as such take great joy in disrupting our "perfect" world. It's not unlike the kid in school who's a neat freak (exessive to the pont of really standing out amongst his peers) and the bullies decide to have some fun by messing up his hair, denting his lunchbox, etc. While that analogy may not be a perfect fit, the NSX does make you standout as "different" from everyone else and that alone invites these bullies-- i.e. "What's wrong with you anyway, why don't you just buy yourself a nice SUV like everyone else?"