Update your sound system while preserving factory functions with these Kicker smart-radio accessories for car stereo systems. When you connect the smart-radio amplifier interface to an OEM factory radio, it automatically determines the correct resistance load for your aftermarket amps and sound processors, producing a clean and consistent sound. We carry 2-channel and 4-channel smart-radio interface modules to handle however many devices you need. Get smart with factory stereo upgrades with great products at great prices from OnlineCarStereo.com.