The aux heater was an option for cold climate markets - I don't think it was offered to the UK. It's an independent diesel or petrol powered engine & cabin heater, i.e the engine doesn't need to run for it to work. It heats and circulates the engine coolant and turns the interior fan on. I think it was made by Eberspacher...
https://accessories.volvocars.com/pt...CC-425319/2006
PCC came with the keyless entry / start option, you just need the fob in your pocket.
ACC also had Collision Warning with Automatic Brake packaged with it, so it does an emergency brake procedure if you don't react when for example a car in front has stopped in a motorway traffic queue - that's useful to have
