Originally Posted by S-Dot
They're only heated when you activate the defroster, which I'm assuming you did?
Mine work splendidly. It's been around -20C here for high temperatures all week, and there's always a good coating of frost when I park outdoors for even a few minutes. It's gone very quickly once the defroster is engaged.
On US models, they work on the F30 "whenever the engine is running" which is the way they always used to work here until the e9x came along. With E9x, they only came on "under certain conditions". I'm glad we got them back all the time here. I'm also glad we never had to turn on our rear defrosters to make them work, I'm always paranoid about my rear tints.