Miley Cyrus, Justin's very, very good "friend," celebrated reaching the legal driving age yesterday.

Ever-popular underwear model Gaston also attended Crystal Rock Audigier's bash for her 16th the night before...while shirtless.

Justin's pecs were a nice present for Crystal, but that's nothing.  Miley can stick her tongue out at Justin whenever she wants.  Plus, Miley's daddy bought her a recording studio of her very own, In Touch reports.

“No, she didn’t want a Mercedes, she wanted a recording studio,” Billy Ray Cyrus explained. “She just wanted a place to record there at the house. She’s been writing a lot of songs, a lot of really great material.”

Just don't expect dear ol' dad to be cutting any of his own tracks in Miley's new studio.

“He’s not touching it! It’s mine," Miley jokingly screeched. “No one’s touching it but me. They’ll ruin it. It’s gonna be dope! I’m so stoked!”

Miley's latest album, Breakout, was released in July. Having sold more than one million copies, the Hollywood Records set was certified platinum in October.

Happy birthday, Miley!