I have it installed as an additional option on my X over here in the UK. Must say, it did come in handy on a few days in winter but haven't used it since. It did work brilliantly when used though.

You're supplied with a separate remote control with and on/off button. The remote has a range of about 100 meters. You press "on" about 10 minutes before you get into your car and everything is all toasty when you step in! You could also programme it to come on at 2 different desired times though the idrive. I haven't had any problems with battery drain and it doesn't seem to be using any noticeable fuel.

Has been a great little gadget and does provide for some conversation material with friends, but not sure if it warrants a price tag of over £1k. Just my 2p.