IT AIN"T PAINTED.I believe your right about the "Ground Bar" location, But if I ever needed to jump start it, I would have a hard time scuffing the paint off of that location. I was able to find a large ground strap near the positive to attach to.
So far it's worked well.
Also I'm not saying this is an approved by Chevrolet charger, But the manufacture assured me it would not damage the car or the battery. And I've topped off the battery a couple of times so far.
You need glasses.:devil