Tesla's New Feature

This is a play on words. Instead of a 'new car smell,' which is common with new vehicles, the joke suggests that new Teslas come with 'an Elon Musk,' playing on the idea that Tesla is so strongly associated with its CEO, Elon Musk. It's a pun, mixing a literal object with the name of a person. It's funny because it's unexpected and plays on Musk's prominent public image.