Only a few years ago, a client held out a white device and questioned whether I could make it play in his car. I asked him what it was and he said it was called an iPod!
Almost all new cars are now set up with either an iPod interface or at least a generic AUX input. But for those that are not, I have various ways to make it interface. If you have tried the $39 FM transmitter, you have probably already thrown it away.
The make and model of the vehicle, determines what is possible. Some interfaces simply give the ability to have the sound play through the audio system, supply power to and charge the iPod. You will still control changes with the iPod itself. Most iPod integrations are $400-$600 installed.
Shown here, is a Porsche navigation screen with the familiar iPod titles. The iPod is plugged in and stored in the glove compartment, it charges while connected. All of the Play lists, Albums, Artists, etc., are controlled through the radio. Cost for this vehicle and others with similar capabilities is $1,000 installed.
For Land Rover's and Range Rover's with a touch screen navigation system, not only is the iPod controlled on the touch screen, but it is also capable of playing video from the iPod. Movies, music videos, slide shows and any other images can be viewed. Cost is $1,800 installed.