If you are talking the top-dog "Street" classes, you better have a thick pocket book and be well into the 6's at 200MPH+. Sure they aren't really all that streetable, but still raced in street classes.
IMO, a street car is something that is seriously driven on the street, not something that is only trailered but runs DOT tires. Heat/AC don't really matter. At least most of an interior needs to be there. Cage shouldn't have any bearing on a car being a street car or not.
IMO fast is 9's at 135+ MPH. Freaking fast is 8's at 150+MPH (talking street cars that fit my loose definition). 7's or better is insane. 10's @ 125+ MPH is quick, 11's at 115+ is pretty quick, 12's at whatever is alright. 13's is ehhh, 14's is you need mods, 15's and slower....get the fawk off the track, you are taking up valuable space.