The window liner is dirty and the dirt in the liner is scratching the tint on your car. You can take it off and clean it. But if it is the teflon window liner it will get dirty again and begin scratching your tint again. I'm not sure about Cobalts but on my ion I had the same problem and when I had my car retinted I had them replace the window liner from teflon to felt strips and now I have no issues.
Hope that helps!
Competition Package|42lb injectors, 2.9 pulley,ZZP DP, Thermal R&D Cat Back
TTR Engine Mount, OTTP Stage 2 Rotated Mounts, Tien Springs, TC Shock/Struts