Dysfunctional dashboards and other problems
Lots of cars — the 2006-up Honda Civic or 2003-up Mazda 6, for example — include heating and air conditioning controls in the console along with the factory stereo, making it difficult to install a new stereo. Owners of these cars can rejoice, because dash adapters are available that allow you to install an aftermarket stereo while retaining your heating and cooling controls.

The climate controls in this Toyota Avalon are joined to the factory radio, making it a little more complicated to install a new stereo.

Many other vehicles (General Motors SUVs in particular) incorporate audible safety warnings, door chimes, OnStar voice prompts, and other features into the factory radio. Replace the factory radio and you lose major functions. But you can now find a variety of adapters that allow you to install a new stereo and still maintain these factory systems.

Getting the Sound Right
Most complaints about factory sound systems cite poor sound quality, and even expensive "premium systems" can suffer from boomy bass and poor imaging caused by inexpensive drivers and too little power. To compound the problem, most factory stereos don't offer the equalization controls you need to get the sound right. Here are a few easy fixes that can improve your daily commute.

The Achilles heel of many factory systems is bass. A powered subwoofer can improve the sound in your car dramatically, even if your vehicle has a "premium" system. Why? When you turn up the bass on your car stereo, you lower the effective power of its amplifier because it takes more juice to produce bass. With a powered sub, you can leave the bass set to "0" on your factory stereo, and let the sub bear the brunt of producing the low-frequency response you want to hear. You'll get a much cleaner overall sound.

This powered subwoofer houses a speaker and amplifier in a remarkably small enclosure.

Any powered sub worth its salt will offer "speaker-level" inputs, so you can connect to the factory system by tapping into the speaker wires. Powered subs range in size from small enclosures designed to fit under a seat, to larger units that install in your trunk or rear cargo area. For many vehicles, you can use a "custom-fit" sub, a molded plastic enclosure complete with speaker, that installs in the rear side panel or under a seat. Powered versions include an amplifier for an all-in-one bass package that doesn't take up any space.

Improving clarity with tweeters
Check out the way you've set the tone controls on your factory stereo. If you see that the treble control is all the way up, consider buying a set of tweeters, small high-frequency speakers that you can install in your doors or dash. You can wire them together with your door or dash speakers, and you'll be amazed at how they'll bring your system to life. Even if you already have factory tweeters, installing a set of high-quality tweeters in their place can improve the clarity of your system dramatically.