Oh, Miley ... shouldn't you be taking holiday pictures with your cute fiance Liam Hemsworth?!

The "Can't Be Tamed" songstress hit the L.A. roads with an inflatable companion instead. We know it's just a naked doll, but we'll keep it clean with snowflakes!

Ms. Cyrus posted the above pic and the following: "Does this count for the carpool lane? Such a nice Xmas gift."

Um, no. Ho, ho, ho!