Which is faster: the 2005-2009 Ford Mustang GT or the 2006-2009 Chevy Impala SS
#2
Safety Car
Both being bone stock they are pretty close in 1/4 mile times. The Mustang is a much better platform and offers much more in the aftermarket world. Unless you need a 4 door people mover I would pick the Mustang over the Impala any day of the week.
#3
Drifting
I had an 08 Impala SS....for the money it wasn't a bad car. Ran it to 190k miles. An 08 Mustang GT will edge out an 08 SS both 0-60 and down the 1/4. If you don't need the room ( I did both carrying kids and family and business) get the Stang!