Hand-me-downs usually involve old jeans or stretched out sweaters, not luxury vehicles. But in Miley Cyrus's world, family members pass on their old Porsches! Miley scored her learner's permit just a few days ago, and her mom has already given her the keys to her Porsche Cayenne. "Tish [Miley's mom] got a new car recently, so she's giving Miley her old car," a source tells People. "She's so excited. Her mom let her drive to work when she's with her." Miley's birthday just keeps getting better! We wonder if she'll still be celebrating by the time her next b-day comes around…