First you should have a general idea of the components. The components are the following: subwoofers, speakers, tweeters, amplifiers, iPod adapters and so on. Surely all these parts and add beauty and a special dimension to your original audio system. You have already the option, that is you set for the factory audio system. But it is obvious that the aftermarket audio systems are always superior to the factory ones to a great extent. If you just do not want to change the whole one, you should be the one looking for the components which is matched with the internal and external specifications of the car it is housed in. Then the components can also work and perform at its best. People have different tastes of music at different period of time but the good system is a necessity. Anyway, take your time when you decide to get your car a good system since it plays an important role in the improvement of the driving experience. So do not do it in a hurry. Then as to the car audio system replacement in the car, it depends on the type and model of the vehicle that you have. Remember to get the right tools and have a better understanding of the technical data.