This is the way a retro touch on a modern car should be executed! The grill area says "2nd gen" without being too obvious. ie, chrome trim all over the place. My only negative comment is that the lights look very much like the Cougar's. But I do like that you included the indentation just aft of the front axle. It connects this car with the Solstice as the future of Pontiac design. I wish the other models would have that.
btw, I don't think you should put this in the contest as it is born to be a Firebird. The Banshee is destined only to be a concept. This design is, for lack of a better term, too good for this contest. Save it for a Firebird contest.
I would definitely have to say congratulations to you on a sketch well drawn!!! You have a lot of skill in both drawing and coming up with a very appealing design. If Pontiac were to make and sell that car (under any name) I would definitely buy it. WELL DONE!!!! Keep up the good work.