Radio Head Units Available here. Over the years, radio head units have evolved from two simple knobs and a moving indicator to high-tech digital devices that handle everything from CD’s to GPS displays. This is in addition to still picking up the local football match over the radio waves. In addition to their functionality, radio head units can be used to give your car’s interior a sense of style. Modern cars allow for the units to be easily removed and swapped for one with a different look or one that has different features. Check out our online selection of radio head units. We know you’ll find the right one for you.