is there any more precise way to describe it other than a buzz? ticking, knocking, metal on metal, something ratting around, electronic type hisssss? It's gonna be real tough for anyone to be able to tell you exactly what it is without hearing it, unless they guess correctly. I'd suggest checking your headers for an air leak, especially around the flange where it bolts to the H-pipe.
You said that it comes when your car warms up. So it isn't there at all when the car's cold?
Thanks for the compliments on the car.

The color is "Corvette White". WAIT.... don't shoot me guys! I know it's a chevy olor, but it was like that when I bought it. Honest.
