I've actually never seen this info posted here, on bimmer.org, in my manual or in the Bentley manual.
On the auto climate control, if you set the temp to 59 degrees (the lowest it will go), and the outside temperature is below that, will the climate control add heat to get the temp to 59? or is setting it to 59 basically telling the climate control to just "give me the outside air at whatever temp it is". My old Saab had a setting called "lo" rather than a specific temp at the bottom end to address this. If not, I guess its not possible to force the heat to be completely off.