This is the rubber part that goes around the edge of the glass itself? To bridge between the glass and the frame on the outside of the car?
If so then yes, any windshield place will have it, and they generally refer to it as a gasket. There are are few different generics shapes for it which may or may not exactly duplicate the original.
Maybe it's a coupe thing but my solstice does not have one installed, and a lot of cars built in the past 10-15 years or so won't either. As manufacturing tolerances have gotten tighter and pennies pinched harder it's been done away with.
2007 Solstice GXP
#3 ASP, DET and NWOR SCCA
"It's a Kappa - not a classic"