Ok, after seeing what Charlie did, I couldn't help myself.
Seeing Mark's car in white reminded me of my kids and how every so often they'll ask me to print something to color. It always ranges from flowers and mermaids to monster trucks and dinosaurs.
So I decided to print out Ben's sick artwork, gave one to each and told them to have at it.
First up is Claire, who just turned 6 this week. The red crown looking design on the fender is fire, and if you look to the right a little bit you'll see some faint yellow lightning bolts.

She was very proud of her design, using her current "favorite" colors, that she signed the hood.
Next up is Nolan, who's 8.
His is pretty straightforward, don't know why he chose the base color he did, but he did manage to add a little green up front, which has always been his favorite color. He told me the number 12 on the door was to make it a race car.
I hope you all get a kick out of this like I did. I'd like to apologize to Ben ahead of time, but I think his job is safe for a few more years.
And to Mark, if you'd like to use any of these designs, you have my consent.

Thanks for contributing and always answering our questions!