If you don't have dual displays, you can directly connect the WxWorks XM receiver to your unit. No switch/hub required. If you have dual display, everything has to be connected via switch. You buy can buy any switch from an electronic store. They'll either be 12V or 5V. 12V switches are harder to come by, but they can be wired straight to your power bus, with fuse. You'll just do what the previous poster said and snip the power cord and connect the pos/neg leads to your bus. Most switches will be 5V, so you need to convert the voltage from 12v to 5v. I achieved this by modifying usb car charger, documented in another thread.