When I had an XBOX in my '95 Grand Cherokee, the installer wired the power inverter to the accessory ignition. So when the key was turned to accessory, or the car was running the power inverter was getting power. If I knew I wasn't going to use it for a while then I could cut the power switch on the inverter off. Hope this help, I have no idea what wires you would need to splice into on the TB. Good luck, I'm sure you could pay a local car audio shop a small fee to have them do that.