I had a friend that had one that I believe he bought new. It was the coolest car I had ever seen back at the time. I was young, and it looked like a Lambo or something. His had a big wing on the back like you described.
Looking at it later, it was basicallly just an optioned out firebird with a body kit. I think yours may be something a little more special because of the banks stuff. My friends was just a stock smallie.