Figuring out what you need: The "ideal" car audio system is not necessarily the loudest one, or the most expensive one. It's the one that best meets your needs. So, the first step is to figure out what your needs are. Start off by asking yourself: what is the one thing you want your new car stereo to do for you? If you don't come up with an answer right away, then start by taking a look at your current system.