The Seven Key Questions to Ask Yourself:
1. Determine how much money you have to invest in your system.
2. Decide whether you are seeking "audiophile quality"
or the modern equivalent of the AM radio.
3. Are you an "audio enthusiast" who wants all the bells and whistles, or is FM stereo the highest in sonic fidelity for you?
4. What types of music do you usually listen to? Are you strictly jazz or do you love thrash-metal? Somewhere in between?
5. How long do you think you'll own your car or the equipment you purchase tomorrow?
6. Lastly, what special things do you have to watch out for with your car stereo? Does it have odd-shaped openings for speakers or the "head-unit?"
7. Is your car or truck designed to accommodate after-market systems?
Once you've answered these questions, you'll be on your way to making an informed buying decision.
Audio equipment comes in a wide range of prices, quality, and performance, from the least expensive mass-produced CD players, tuner / amplifiers and all-in-one systems with navigation and even TV screens, to precision-crafted "reference" components costing several hundred dollars. The key is to obtain the best possible sound quality at the most reasonable price.
After considering the points above it boils down to the following when upgrading your sound system. The first is getting the music into the car – via radio, tape, CD, MP3 player or mini-disc unit, etc. The second is getting the music out of the car – via speakers, amplifiers (amps), subwoofers and so on. You can upgrade either of these areas alone, to some extent, but best results will be obtained by planning a co-ordinated approach.
Once it is installed in you vehicle you will have to bear in mind the following. Your expensive sound system may not be immediately similar to thieves, as speakers, amps and subwoofers are often hidden from casual view, but one thing that will give the game away is your fancy head unit. One look at it will say "I've got a really nice sound system installed in here!" For this reason, many head units are detachable, even on moderately priced systems. Push a button and the whole front fascia pops off to be safely hidden out of sight or taken with you when you leave the car.