He doesn’t have to sue Detroit. He sues the ad agency and graphic artist who stole the image. Image theft is rampant and should be stopped, just like the theft of any other property. Lawsuits are a good way to let it be known that no, you just can’t swipe a copyrighted image and make a profit from it anymore than you can publish someone else’s book under your own name and collect money for it.
evidently I missed some of the details
“None of his work was used actual production.
See the article, about paragraph 5.”