Hi Adrian,

What you've described is exactly what I've witnessed. Mine is mapped so the top two switch sources, the volume is self explanatory but when you press them together is simulates a down press. The roller simulates left and right presses. The bottom button toggles shuffle.

The roller is a little tempramental it always works in one direction and then its flakey in the other, although it's been behaving itself recently.

If you're suffering from the same problems then it's unlikely to an installation fault. On the subject of battery icons, since I connected it directly to the battery it doesn't appear very often now, usually only when i'm starting the car.

The only mildly annoying thing is the radio is distorted when it starts up, although it only lasts a couple of seconds.