looking into buying an 09

Ok lets try this again, sorry admins. Im looking into buying this 09 Gt premium sitting here in town. The car is White with black stripes, auto, 3.55 rear ratio( I think), has 21k miles on it, and they want $24k for it. Iv always been a manual trans guy but looking to change over. How do you guys like this transmission? is it reliable for more power? How well do these cars handle mods? are there any necessary mods? Im an advid drag racer and the car will probably be at the track everyy weekend and will be looking to get the car in the low 8s high 7s in the 1/8th. How well do these cars like the spray say a 100 shot or so? sorry about all the questions this will be the first newer mustang iv ever owned if i do decide to buy it which im pretty set on it. Thanks Guys
 
I will answer for all the looks and no replies. Instead of answering each question individually there are countless threads regarding the 3v power limits, gears, weight reduction, and pricing. Not trying to be rude but it would be tough to answer all at once.