Ok so here goes.
The iPhone will only work with the tune point lead for sound and charging. The standard iPod lead will only charge.
Once iPhone is connected via tune point it will start to charge. You can access the whole menu but once you select music it will come up with a accessory connected screen meaning you can't select tracks via phone, only stalk control. The lower button on the stalk will not change playlist or artist, therefore you have to select this on the phone before connecting.
Plugging in a USB stick and you can access both skip track and next album/play list.
Having both connected and the USB stick takes priority. You can change from radio to cd to USB but iPhone will not get recognised, even though it is connected and charging.
Every now and then the tune point will not recognise the iPhone or USB stick and give a single beep. Just turn off the stereo and turn it instantly back on and your good to go again.
I have fed the tune point lead through the back of my head unit and velcro'd the tune point box under the glove box.
Hope that helps