Simple, Intuitive and Functional. These are the three little words I would use to describe Griffin Autopilot car charger for iPhone (original, 3G, 3GS) and iPods (w/ dock connector). I've been searching high and low for a cord based charger that offers an aux-out and for whatever reason, I had a hard time finding one. That is until Griffin released the AutoPilot. The AutoPilot is very similar to the iTrip AutoPilot that I reviewed some times ago in that it differs by the way it handles sound output (FM Modulation from the iTrip AutoPilot). If your car comes with an Aux-In port, get the AutoPilot for the best and un-interrupted sound.
The AutoPilot is intuitive to use, simply plug in the car charger into any 12V cigarette lighter socket in a vehicle. Plus the dock connector to your iPhone or iPod. Use the supplied 3.5mm audio cable to connect between the charger's aux-out to your vehicle's aux in. When you turn the car on, it will power up the AutoPilot with a glowing red LED ring. On the back of the charger, there are basic controls acting like a wired remote navigate your song choices (FF, RW, Play/Pause), this is especially helpful for touchscreen devices and far cheaper than the OEM integration solutions but comparable in performance. The only thing you should play with is the high and low aux-output setting to match your audio systems sound output; I leave it on high setting for my car.
The AutoPilot in concept is simple but it just pulls everything together in a perfect way. It provides 3 solutions in 1 (charging, line-level audio output and controls the iPhone all at once). As is with any car accessories, obviously if you have limited number12V outlets, the AutoPilot will compete with your existing devices such as a GPS unit for power. Also, the location of your 12V plug will also determine how useful the control will be (ie. some aux-ports and 12V ports are designed to be within the arm-rest storage area). As far as I'm concerned, the AutoPilot is the best $49.99 MSRP (Amazon $32 shipped) solution you can invest for your car.