How do I convince my parents to let me get my cartilage pierced?

I really want to get my cartilage pierced. I would never do it by myself and would definitely go to a professional such as Piercing Pagoda. I already have my earlobes pierced. I want my catilage pierced so bad!! But my mom thinks it might look trashy. How do i convince my parents to let me get my cartilage pierced!!! thanks -- Jenn