Cooling fan is still running 30 minutes after I took out the key

Sounds like you have a cooling fan relay that is stuck You need to have a shop find the relay that is sticking. There is usually a relay box under neath the hood, the cover will identify which relay is which. But I would not just replace the relay, make sure you have a shop inspect you BMW, because a sensor may be defective that turned on the relay until it over heated and now sticks in the 'on' position.

yes an its still running