iPod interfacing can be a very difficult concept. With all the different products out there, most people dont know where to start. Plus, there are so many different vehicles, its hard to know what goes together. The three main categories of iPod intereface adapters are: wireless
FM transmitters, wired FM modulators, and direct audio inputs. All three categories have their pros and cons.
Wireless FM transmitters are horiable. Most of the time you get a ton of static. The fault of the product is out of the manufacturers hands. The FCC limits the output of the transmitter, and radio stations transmit higher than the FM transmitter. Usually people put up with this
inferior device for a short period of time. After a while it will piss you off so much you will pay anything to get your iPod to work correctly in your vehicle. Even though FM transmitters suck, they do have one strong point. Static or no static, they will work in any vehicle. Also, since they do not have to be installed, you can take it from car to car.
The next device is a wired FM modulator. A wired FM modulator is wired directly in line with your radio's antenna. The FM signal coming from the vehicle's antenna is interupted by the modulator. The iPod's is sent through the antenna input on the vehicle's radio, not transmitted wirelessly. Since the vehicle's radio is not connected to an antenna, no matter how strong a radio station is transmitting, it will not interfere with your iPod's audio. With a wired FM modulator your iPod will have absolutely no static, but it does have its cons. Have you ever noticed that FM never sounds as good as a CD? The audio quality of the FM tuner is lower than your iPod's audio quality. The iPod's audio will only be the quality of the FM tuner. If your iPod contains, very clear, CD quality, recordings it will only be as good as the quality of your FM tuner. I recommend a FM modulator if your vehicle does not have a provision for direct audio input. A wired FM modulator is a good option. It is not the best option, but sometimes its the only option.
Direct audio inputs are the best type of adapter to allow for your iPod to be connected to your car. Using a direct audio input will give you the best sound without any interferance or static. Basically, a direct audio input connects to the vehicles radio using its stock cd changer
or satellite radio port. These inputs have good sound quality which will allow for the audio from the your iPod to be as clear as possible. Some direct audio input adapters are designed specifically for iPods and come with a cable that will plug into the bottom of your iPod. These adapters will charge your iPod and allow for your iPod to be controlled from your vehicle's radio.
Decide which iPod adapter is right for you can be hard. It is my recommendation to get the best adapter possible and to do it right the first time. The best type of adapter is a wired direct audio input. If your vehicle cannot accept one, the next best thing is a wired FM modulator. Due to my negative experiences with wired FM transmitters I cannot recommend ever using one.