to run 9s, the current automatic would never hold up-- a strong manual or a purpose built automatic is important..
9s is possible--but difficult, and depending on the shops near you--can become very expensive.. but streetable? id recomend getting lite--taking alot of weight from the car-throwing away some of the luxury..-air cond-power seats-anything you dont need.. your car is somewhere around 4000 lbs.. to run 9s will require alot of HP.. im just guessing, but i think well over 1000 hp.. and the rest of the suspension? i think it may hold up? but your gonna find out..
and running nines may sound nice, but youd be doing 140 mph+ in 9n seconds.. that can become uncrontrollable--quickly..
if i were you, id settle for 11s..that should let you race and beat almost 99% of the cars out there-street.. and getting there with 2 turbos is very possible-while keeping the luxury aspect of the car intact..
i have seen new Mercedes run high 11s at the track at 119 mph.. this was a twin turbo..and we know they are heavy cars also..
after your running 11s, you feel the car is not fast enough-- then you can start adding some nitrous.. but i think when you start running 11s, your gonna feel its fast enough..