I inspected some of the part numbers suggested above (many were discontinued) and also considered some of the MacGyver methods, but the MacGyver parts were not available locally or were quite a bit more expensive. These "sort of" work, you have to force them over the airbox studs with copious force and lube, and the pressure and weight of the airbox and intake plumbing keeps them in relative compression/location correctly. I suspect they will fail soon because of heat and being so stretched over the studs, but for now they are working fine. I paid about half of what this link indicates:
https://a.co/d/atg9yTn

 

The 2.0L part is not available any more for HHR SS models, but I found the standard insulator (12563914, Chevy dealer suggested I try it) works just fine on the 2.0L airbox.