Original radio modification

Thanks for the ideas as much as I'd love to do the joes radio route and have my original modified to Bluetooth it's way to expensive for me and I'm more the diyer anyways lol I like the amp idea superchargeddrt! How so does the radio just supply the power to the amp and your phone does rest?
The radio audio goes into the box and the box is supplied via a pig tail that connects to the radio power. You don't even have to connect your radio to it if you don't want. This box is small and light and could be easily mounted under the package tray with only the speaker wires, 12 volts Switched by the ignition and a ground leaving your factory radio to play through its original dash mounted speaker.