ThanksHave you got a keyless system on yours? On mine I just turn the key one notch. You don't have to turn it more and start it just to open the windows. But as said above you can only leave it like that for a time because the ECU will turn it off to stop the battery discharging too much.
I do this to pump the tyres up regularly as I don't want the engine running but need power to the 12v socket.