After a bunch more digging, I've found a couple possible options. If anybody has any additional ideas, please let me know. If I don't want to cut wires, I'm thinking something like getting one of these and cutting it up. Does this seem like it would work?
http://www.installer.com/item/display_i ... it=gmcss-2
Metra also has a harness, but it only includes the end that plugs into the radio.
Has anyone else put an F500 in a Cobalt? If so, where/how did you mount it? Right now, the only place I can see doing it is dead center above the vents and radio. Ill send out pics wh