I finally found the CHMSL Relay for the High Mount Stop Light.

It is in front of the driver's side shock tower under the AC lines.

It is cover with a black plastic cap.

Under the cap is the relay and a location for another relay. I believe the empty location is for a rear power outlet on an HHR Panel model.
I'm including pictures.

I was able to cross the AC Delco to a NAPA part number. Napa's part number is AR606

The uncovered relay for the high mount bulbs.

The High Mount Stoplight Relay with it's cover over it. This is probably what you'll see looking under the hood.

A shot showing the location of the relay assembly. On the left is my driver's side strut tower. The black cover at the bottom is the underhood fuse cover.

 

 

Only 2008 onward, the other position is for the rear access door locks on a panel.

 

what is chmsl probably obvious but I do not know what it is

 

CHMSL===Center High Mounted Stop Lamps

 

thanks keep the info in memory mine is all ok for now

 

I asked myself the same thing. Acronyms are OK but sometimes you're not aware of what they mean. Had to Goole it to find out.
I do know what SNAFU means though.