Now, I'm in no position to give parenting advice, but...
Seriously, fucking control your children, douchenozzles.
First of all, why are you bringing children to a car dealership? It's boring and involves sitting there doing nothing for hours. No child WANTS to do this, especially on a weekend when they spend all week in school doing the same thing.
Hell, when my mom dragged me to a dealership when I was in my late teens I was still bored. I can hardly imagine what kind of hell it is ten years younger.
Second, bring them something to entertain themselves with. We have a few shitty toys in our service lobby, but not much. If you expect them to sit and twiddle their thumbs for several hours, give them something to do! A book, a game, hell even a coloring book! Instead of them sitting and playing in a controlled manner, they're running around the showroom- literally. This is bad.
Third, if you have your children with you and they begin screaming, for the love of all that is chocolate CONTROL THEM. I can't tell how much of a headache it gives me to sit in front of a computer all day copying things from papers to the electronic version and vice versa. Having to listen to your crotchfruit screaming while I'm doing this makes in infinitely worse and I am required to smile and be friendly regardless.
Am I being overly sensitive with this? Maybe. But can anyone honestly say they like having to keep an eye out of running children while carrying hot coffee?