Very common issue with E46s. Like everyone said its due to condensation build up from oil. CCV is supposed to do its job and separate the vapours but the car needs to be driven for a while before it starts working as the CCV is vacuum controlled.
If your CCV has not been replaced and you;re at over 120kms, change it. I did it last week with the new Cold Weather version so that I dont have to worry about it.
Also, correct oil is a must. For our canadian weather there is NOTHING better the Castrol 0W30 Euro Formula (the back of the bottle says Made In Germany) sells at crappy tire.
On the RIGHT in the picture below.