It's more likely oil based on our 2002 330i experience. Oil filter housing gasket is suspect. Need to get it on a lift to inspect and tell for sure where its coming from which is easy to see once the car is up in the air.
Should not be a problem driving for many miles.
"sometimes you're the windshield .... sometimes you're the bug"
2014 328i Mojave Metallic
2009 328i Black Sapphire Metallic
2007 328i Black Sapphire Metallic
2007 Honda S2000 Berlina Black
(Hey Jim... am I diversified?)