valet（回答）

女王様から指名をいただきました。valetは「(貴人の身の回りの世話をする)従者」を指す単語ですが，そこから転じて「(ホテルやレストランの)駐車係」という意味があります（『プログレッシブ英和中辞典』小学館）。
スポーツカーに乗るチャンスを得たと言う点でvalet attendantの気持ちはわからないでもありませんが，やはり仕事は責任を持って全うしなくてはいけませんね。（Koyamamoto）

Watch a Valet Attendant Take a Joyride in a New Corvette
Car owners may have second thoughts about dropping their rides off with the valet after seeing one new video.
Dan Cowles left his new Chevrolet Corvette Stingray with a valet when he and his wife, Sandy, went to see a concert in Costa Mesa, California, Sunday.
The attendant decided to go on a dangerously fast joyride inside the garage without realizing that Cowles had activated the car's “valet mode.”
The special setting locks the glove box and certain systems within the car while also activating a forward-facing camera that records what the valet is doing.
Cowles didn't see the footage until he went home after the concert.
"The first thing I saw was that he went 50 mph, he went 0 to 50, which is pretty obvious what he was doing," Cowles told ABC News. "When he parked the car into the stall, he went out of the car and looked at the front end of the car … I was concerned about damage about the front of the car, but fortunately there was no damage."
http://abcnews.go.com/US/watch-valet-attendant-joyride-corvette/story?id=27643448