Won't these fit as well? Look like the same radio, produced by Panasonic.

 

U have to have a Cobalt radio in the Cobalt . I swapped to an 07 HU and I did try with the HHR hu . The curvature of the face of the radio is flatter than the Cobalt version , so it doesnt even fit the bezel right . The electronics are not compatible either .

 

What about the ones from the G5s? I assume those are the same... LKQ has one on clearance for $50.10

 

Yep , G5's are fine . Get the part # though and verifty with a dealer . Even though most of the "black tie" head units look the same , theres countless variations that differ in size and electronics .