While some of Arkon's individual components look as if we've seen them from other companies before, we'll admit to being intrigued by the overall direction its iPad and iPhone vehicle mounting lineup is taking. On the iPad side, the company has the Headrest Mount with Custom Fit Holder ($40, IPM-RSHM), which impressively solves the "how do I hang the iPad in the back seat of my car?" question with a custom hard plastic headrest mount that requires…