The real question is what else might need to be done to the vehicle. A 2006 HHR retails for 3-4k with unknown issues. If your cost of all problems to fix it are more than that then move it out to someone as a project.

I hate car payments and havent had any since 2007. I usually have to put between 200-500 in my cars every year for maintenence and other issues and i know that this is 1-2 months car payments so that i stay ahead of the curve.
Sure I dont drive the latest but I dont care for new cars anyway.