I had CircuitCity install mine because I didn't have time that week, and wanted it in. I might take apart the dash and see what I can find. I think the mute line is in the amp, not just a wire you can tap. I may be wrong. Also, I have heard of people tapping into the driver and passenger speaker wires on other toyotas for parrot kits, but I have never done this and was afraid to get into it. I may do some more research and see what I can find. If you have anymore knowledge of it, please post and let us know.... Enjoy the kit.