Keep your car amplifier installation cost down by doing it yourself with Hertz audio accessories. They make a variety of products that are essential for performance sound. Their waterproof amplifier fuse holders can be used on or off the road to protect sensitive electronics. You can also get remote controllers to set subwoofer levels or overall volume. Get these accessories from OnlineCarStereo.com along with sound processors, cables and more that ship free in the lower 48 states.