Disregarding the horrible top gun music... That car was designed 40 years after the Camaro. The lug nuts (1 per wheel I might add) are threaded differently on each side so they cannot loosen due to being driven in the forward direction. THAT is how much attention to detail there is in that car.
YouTube - Grand Prix GTP exhaust, TOG headers and Borla catback
Not too bad.
YouTube - Grand Prix Exhaust Borla Pros vs Stock
Almost too deep for my tastes though.
YouTube - Corsa catback
Audio quality is pretty ****, but not the most impressive either.
This is pretty much how you should decide, listen to the different systems and make up your mind on what you want.