Needless to say, they don't like it.
There is a reason valet mode exists. It's to keep your car safe from valets who might want to hoon it or pop the trunk and see what's inside. Some systems are more advanced than others, like Chevrolet's valet mode in the new Corvette that can actually record video. The system in the Challenger Hellcat isn't that fancy but it does the trick, especially when paired with a dash cam. The pair in this video work at Universal Studios and were more than a little disappointed to learn that the car they were valeting was in valet mode.
The duo don't try to take the car on a joy ride nor do they hatch any nefarious plots to wreck the car. The owner of the car actually blurred their faces out of the video and didn't tell their manager because they didn't "do" anything wrong. That sounds like a cool guy to us. Other people haven't been so lucky.