HEAD UNIT
The head unit is the most important part of the audio system. It is the in-your face-equipment and also the device you will be most 'in-touch' with. It is a good idea to look for a unit that is aesthetically pleasing, blends with the décor of your car, and has features that best suit your needs. Most importantly, the layout should be user-friendly, easy on the fingers and simple enough for you to operate it without taking your eyes off the road.

Head Unit Features:
• CD Changer Controls - Whether you get a CD, cassette or MD (??) head unit, it is better to go for a model that has CD changer controls. They come at a little extra cost but give you the option of simply plugging in a changer in the future.
• Power - Typically a head unit has an output of about 5-7 watts RMS per channel, while a high-powered head unit goes up to 13-15 watts RMS per channel (even if they claim 35 or 40 watts).
• RCA Outputs - If you are planning to run the speakers from the head unit's built-in amplifier, you don't have to worry about RCAs, but if you plan to add amplifiers in the future, get one with a set of RCAs (left and right), three sets preferably (left and right for front, rear and subwoofer).
• Detachable Faceplates - There are many security options for head units nowadays. None of them are 100 percent effective in deterring thefts though. Detachable faces are the most common option. The front part of the radio comes off, rendering the rest of the unit useless.

We are already familiar with the different types of head units, but here's a quick glance at some of them.
• Cassette/Radio Player
• Single CD/ Radio Player
• Single CD (with MP3 capability)/Radio Player
• Double DIN (Cassette/CD/Radio Player)
• Single CD player (MP3/CD/VCD/DVD)/Radio Player
• Single CD Player (MP3/CD/VCD/DVD)/Radio Player/Flip LCD Screen