The brake lights and rear turn signals on my 2011 HHR are not working. (Front turn signals work fine) I doubt all the bulbs burned out at once, and I thought it might be a fuse. However, I can't seem to locate a fuse that applies. What should I check?

 

If you have no lights at all (including 3rd brake light, parking lamps and reverse lights) then I would be looking at the main wiring harness that runs to the rear of the car.
Either the main harness has somehow unplugged or the grounding wire bundle has a bad connection.
The rear ground bundle grounds to the body back by one of the rear tail lights, inside, behind the trim. (sorry, I can't remember which side it's on )

 

Did you look in your owners manual for a description of the fuse locations?