Just on that last point, where I live the temperature is generally in the 5-15 degree centigrade range. My understanding is that this is a good range for heat pump efficiency - not too cold and not too hot. Am I correct?

Again - thankyou for your comments.

I am better educated on the subject now than if I had rung 25 UK BMW dealers at random - and I suspect - got 25 different versions of B/S for my troubles!!

Thanks for the responses.

Am I right in saying the Aux Heating was fitted as standard to US spec cars?

Thanks for that.

Most dealers in the UK - (where it is a £500 + option and rarely specified) - say it is only for pre-heating !!

Apologies if this has been asked before but I am trying to get my head around the heat pump option and am getting mixed messages from the BMW dealers. I understand that the heat pump has an optimum temperature operating range and as I am in the UK where the temp is commonly around 10 degrees that is...