Whether you got a brand-spankin’ new iPhone 4S for Christmas or you’ve had an iPhone for several months or years already, you may know that the iPhone also doubles as an iPod. But the plethora of apps available for iOS users can also turn your iPhone into a much lower-priced music player. Apps like Pandora, Rhapsody, iHeartRadio, and even Spotify can allow you the freedom to listen to several types of music — and sometimes any song you desire — without paying much at all for unlimited music. For those who enjoy different types of music throughout the day — such as while in the office, at the gym, or during the commute home — these apps are some of the best to have on an iPhone.

If you also own your own car, integrating an iPhone into the car stereo is critical if you like to listen to music while driving — especially if you still have your car’s stock radio installed. Today’s radio stations seem to be stuck on the same top 10 songs while also playing more commercials than actual music. Unless you (still) burn your own CDs, you’re likely more inclined to turn off your stereo entirely than listen to it at all. (That is, unless you have a penchant for listening to Katy Perry’s latest single or happen to be studying marketing.) If you’re thinking of installing your iPhone into your car stereo, you have several options.

What is the Cheapest Way to Install Your iPhone into Your Car Stereo?The cheapest way to install install your iPhone into your car stereo is with Griffin’s iTrip, which is an
FM transmitter that hooks up to your iPhone via the dock. The transmitter uses “SmartScan” technology to find the cleanest frequency to play your music through your car stereo speakers without wires. You then tune your car stereo to the FM station, and like magic, the music playing from your iPhone is playing via your car stereo. Of course, the sound quality is the same as any other FM station, meaning you’ll likely hear some static, or even interference if you’re passing by a semi on the interstate. If your daily commute involves multiple tunnels, you’ll also lose signal while you pass through, as the FM signal requires clear access to the sky. Since the iTrip requires no installation or modifications to your current stereo, the price tag of only $49.99 (or $33.41 from Amazon at the time of this writing) makes this option the cheapest.

However, the problems an FM transmitter has integrating your iPhone with your car stereo mean this solution may not be the best. If price is your concern, you may want to consider an aftermarket stereo with auxiliary or USB input (which can usually be found for around $100) and will allow you to directly connect your iPhone to your new stereo. (The difference depends on your preference for the type of cable you’ll have to use to connect your iPhone to the front of your stereo.) The sound quality from your stereo will be exactly the same as when you listen to music directly via your iPhone, and you can still control your apps directly from your iPhone. Keep in mind, however, that unless you install this stereo yourself, you may have to pay slightly extra for labor to install the stereo and replace the stock stereo from your car.

If you’re looking for a more comprehensive solution that allows you to install your iPhone into your car stereo and still keep the price low, you can keep your stock stereo and have something like an iSimple kit installed. One version of this kit is available for most modern cars for around $179 and integrates your iPhone with your stock car stereo, even allowing you the ability to control some settings with the stereo itself. A cheaper option, priced around $140, allows you to connect the phone with the car stereo, but will shut off the FM radio to use the car stereo to play your iPhone’s music.

There are, of course, several other options if you’re looking to integrate your iPhone with your car stereo. You can buy a brand new 2012 Audi already equipped with integration, or perhaps install your own into your current car. Or, do what Chris Pirillo suggests: purchase an inverter for your iPhone and keep a portable wireless Bluetooth speaker in your car. Not only is installation not required, but it’s portable! (Just imagine what your spouse, girlfriend or roommates will think when you bring that bad boy home.)

All that said, should you choose to go any of these routes, you may want to consider a dashboard mount for your iPhone for easy access to your phone while driving. One of our personal favorites here at LockerGnome is the Oona. Looking down at your phone and away from the road (for any reason) is a recipe for disaster.

Have you hooked up your iPhone to your car stereo? Let us know which method is your favorite in the comments.