Belkin's Tunebase Direct is an accessory that allows you to connect an iPhone/iPod to a car stereo with a 3.5mm auxiliary input. Well, you could connect an iPod directly, but the Tunebase holds the iPod up vertically and charges it too. The 3.5mm audio out is connected to the aux-in port found in many newer car stereos, and can only connect in this way - so make sure that your stereo has one before buying. It needs to be plugged into the 12V DC cigarette lighter socket for power which in turn charges your connected iPhone/iPod.
Its simple looking but has excellent build quality. A nice touch is the additional powered USB port to power up other devices. The dock has a vertical clip which holds different sizes of iPods or the iPhone. Simply slide the holder up or down to accomodate different sizes. The inbuilt microphone is meant to accept calls when an iPhone is connected; the idea is that the unit will play the callers voice through your car speakers. Once you're done with a call, the music can resume.
Depending on where the 12V DC socket in your car is, the microphone in the unit could be at chest level (like it was in a Ford Ikon). In this scenario, it can pick up sounds from the fan blower and other ambient sounds. In a car like the Maruti Swift which has the 12V accessory socket placed between the seats rather than on the dashboard, there will be a wire trailing to the aux-in of the stereo which may hamper gear changes. So you need to make sure that it works in your particular case before buying. If you don't have aux-in, consider an FM transmitter like Belkin's TuneBase FM or Griffin's iTrip.