I recently bought a new Pontiac G8 GT that was fitted with the Bridgestone Potenza RE050A summer tires. The car is a decently sized four-door sedan with the 19" wheels and tire option, but I must admit that the Bridgestones make the car handle like it weighs half as much! Road noise is acceptable (at least so far), and wet traction is very good. I have a set of winter tires for the car in case I need it, as I've already found out that the tires are very slick in temperatures below 40 degrees (F).
This Bridgestone is used as Original Equipment for high perfomance cars like the Nissan 350z and 370z, as well as BMW sedans (in a run flat version).
Like most high performance summer compound tires, I'm expecting around 20,000 miles of life (assuming I can keep them rotated often). After these are used up, I'm planning on going to the Bridgestone Potenza RE760 Sport in an effort to get a little better life span out of the tire. The 760 is not quite as "sticky" as my current tire, but still should give me more than enough grip to handle well.
If you're considering a high performance summer only tire for your Pontiac (or any other hight performance sedan), the Bridgestone is worth a look!