What is a great way to give a girl a necklace?

This girl I've super great friends with and she knows I like her has her birthday on June 4th and I'm taking her to lunch at a really fancy sushi bar and then the movies and town square in Vegas afterwards. I bought a gorgeous necklace for her, one to where any girl would be like OMG! But I want to give it to her in a really romantic way ya know? Like have her find it or something. If anyone has any ideas that'd be great. I've kind of thought about attatching it to the visor in the truck and I'll ask her to pull it down and grab something in it and then a necklace pops out. Other than that I don't really know. :/ Any ideas would be awesome. Thanks everyone :)