E60 / E61 (2004 - 2010)
Hello,
I used O'reily's premixed 50/50 Universal coolant to top off my 2009 535i, before watching videos specific to BMW all seemed recommend strongly for using only BMW blue coolant which is got me really nervous.
I don't know how bad it is for the car, and if I should go get it flushed...
I'd...