Red car on pedestal light on dash?
 

I've seen this come on twice recently. It shuts off after a short while. What would be causing this? Could it be related to recent cold temps? Car functions normally as far as I can tell.

Check your brakes. If the brakes are fine, it could be a glitch in programming. I had this issue on my previous 2007 335i. Had brakes and rotors replaced several times, car reprogrammed - the problem was still there. I ended up just reseting the light through the menus every time it came up.

That is a service interval indicator. You can see the details in iDrive via the menu button, info, and vehicle status. Or you can press and hold the trip reset button for 5 seconds and cycle thru them.