I am learning about all this and I am wondering, I think my caster is a little too positive which might be an indication that my rear springs have started to sag. The left caster is more positive than the right caster, and strangely, I was suspecting that my left rear spring was weaker. As if my HHR sags a little to the rear left side.

 

Or your left rear spring is broken

https://www.chevyhhr.net/forums/prob...-spring-58583/