Not sure if I should be worried or not. It used to happen in winter all the time on my old e38, now just started on my e66. The day we we've got 18F temperature outside, the "Coolant level low" warning started to show up when I start the car. The other day it didn't show, but yesterday it did again.

I am going to call the service department anyway, since I got "Passenger restaint system fault" 2 days ago, but with the holiday and everything, I don't know how long I have to wait for my car to be checked. And what if it is a real "coolant alarm" this time?