Mobile audio, the general term for entertainment system in cars has come a long way. Also known as In-Car Entertainment (ICE), it describes the sound system fitted in an automobile.
A good sound system has become a necessity whether you are driving around town, on a highway or just waiting at the signal. The last three decades has seen a revolution in car audio designs starting with four and eight-track  players to the present day innovations including CD and MP3 technology.
Here is an insight into the world of car audio:-

1. A stock car audio is a preinstalled system done at the time of manufacturing; a custom car audio installation can involve a simple upgrade of the radio to full blown audio equipment customisation.
2. Car systems purchased from the market frequently require adapting to the care's interior, one of the major complaints made by owners of luxury vehicles.
3. A weakness in mobile audio system is the spectral balance, as many car audio systems over emphasise the bass and treble.
4. Some of the high tech features available include touch screen display and voice recognition systems, which allow you to control many of the stereo's functions through spoken commands.
5. If you are into really loud music then a subwoofer in the back and array of tweeters across the front are a necessity. A tip to installing tweeters is to place them on top of the dashboard. This allows the sound to bounce back from the windsheild glass and there is minimal loss.