The bag itself can even blow out, I've heard two pop before, and there bloody loud! But most common things are what jeffy mentioned. If I had the cash laying around, I would bag mine, they do look tough when done right! There's a guy in Sydney with a bagged zr6 and it is so damn sexy! I'd certainly do some research and find a reputable installer, at the end of the day they'll be able to answer your questions, it's what they do for a living.