Miley Cyrus and Liam Hemsworth in Mustang Pictures

Miley Cyrus and Liam Hemsworth hopped into a mint green Mustang for a ride around LA over the weekend. The couple went casual during the Sunday outing, which came after a more dressed up Saturday evening. Miley and Liam attended Muhammad Ali's Celebrity Fight Night XIII fundraiser in Phoenix, where Miley's huge accessory on her ring finger sparked rumors that the two were engaged. Miley quickly cleared things up on Twitter, saying that the sparkler is actually a topaz that she's been wearing since Nov. They still had exciting news to celebrate though, since Liam's The Hunger Games took the top spot at the box office and broke midnight opening records. He's still talking about the action movie, and stopped by Conan on Monday night to chat up the film. His costar, Jennifer Lawrence, is also continuing to do press with her latest travels taking her to London.