If you’re ready for better sound or more features but not ready to buy a new car, you can upgrade part or all of your car’s audio system. A new head unit, for example, can provide the latest features and more versatility, such as receiving satellite radio or HD Radio signals, adding an in-dash CD changer, or integrating a portable music player, navigation system, or DVD video. A more powerful amplifier can deliver not just more volume but clearer sound. New speakers are another way to improve sound without necessarily spending a lot of money.

Replacement components and speakers designed to fit in factory openings are readily available for most cars, and some can be relatively easy upgrades. Others can be quite involved and are best left for a professional installer. A great deal of information is available online, in forums and on the Web sites of mail-order stores like Crutchfield and SonicElectronix.com, which cater to do-it-yourselfers. These stores offer a wide variety of components, and some have staffers who can offer assistance through a toll-free call, live chat, or e-mail. Some, like Crutchfield, include adapter kits for different models to ease installation and enable you to plug the new unit into your car’s wiring harness. But it’s best to do some research to determine if the job is within your ability. Even if you buy through mail-order, you can always have the components installed by a professional.