I think it really depends on where you live. I live in a pretty upper middle class part of the East Bay and I rarely get any challenges on the road, people are too mature or busy on their phones. Most people are pretty intimidated by the looks and sound of a Viper and wont bother me. On the occasion I get a guy who's just curious to see if he can keep up with me, but rarely anyone who really wants to race.
My favorite stop light moment was at a three lane light... randomly I pull up to a red next to a Gallardo and a Dinan M3... The guy in the Gallardo was with some chick so he held off so he wouldn't get embarrassed (I'm guessing he wasn't a very experienced driver). Nothing happened, but it was a pretty freak occurrence to have those three cars randomly at the same stop light.
Anyway, get some sticky tires (PS2s or better) and the Viper is a breeze to drive on the street. It's when you start trying to find it's limits that requires a lot of skill and can be scary/exhilarating. Best to do that at the track where you're not going to endanger anyone else on the road while you learn your car. My 2 cents.