The car hasn't been running for over 3 hours but the engine is still slightly warm. Not too hot to touch however. I was washing it and I noticed a whistling sound. I put my ear to the bonnet and concluded it was coming from there! So I opened it up and it was a really loud whistle coming from the right side where I am recording. Very odd. Any thoughts as to what it could be? It was so loud, I could hear it from inside my house, a good 15meter away from the car that was on the driveway! I have a thread on Bimmerpost in the E90 section.