You got 115 views regarding your question. The answer may be that no one has ever heard that the rear view mirror has temperature markings. I never heard of that so it may be a Switzerland thing. You asked a legitimate question but perhaps others are like me. If they never heard of it they wont say anything. Try a search of the internet and you will find no mention of it period.

Hi Barry-

Thanks for the note. It's definitely not a Swiss thing. I'm in the USA and when I start the car the entire little display flashes a sort of self test during which time you can pretty easily see the degree F and degree C markings. I've found nothing in the manuals, CD that came with the car, web sites, etc. on this (possible) functionality. Assuming it does exist and maybe even linked to the OBC, it would be pretty cool if it could be used to display other things like avg speed, consumption etc. Yes I know that stuff can be shown on the display below the gauges, but still that would be cool.

I've asked the question a few times in the past (on different forums and several BMW techs) and the consensus seems to be that it won't function as a temperature readout (the compass display is capable, but the function isn't there). Besides, why would you want the mirror to display the temperature readout when you can get the same thing out of your instrument cluster? Afterall, you got the compass mirror for the compass...so why would you want to turn it into a thermometer?

Its prolly a generic rearview mirror that bmw uses, and I'm sure in other vehicles (such as the Range Rover *HINT*) which shares its mirror until the 2006 refresh, very frequently car companies purchase select parts

Most likely whoever manufactured the mirror made it multi-functional to cover as wide a range of vehicles as is possible. For those which do not display the temperature in the dash then it is available for the vehicle manufacturer to display it in the mirror. That way he gets the maximum number of mirrors into the maximum number of vehicles. There may be no way to make it work in the X!

LOL, the effects of outsourcing I guess! The reason why I would like the temp marking on the mirror is because over here, the temp is one thing I look at frequently (dont care much about the direction considering i've got the nav). Oh well, at least the temp is indicated somewhere on the instrument cluster :)

Hey, maybe it's a headup display thingy that never caught on.....:rofl:

There must be some shark on ebay selling the instructions.....