Sure they can. But You Tube videos can't be your only source. It was the absence of serious reference sources that I cited. You had a serious doctor in your list. But you didn't cite a credible reference for him.

If I want to see what colour the sky is I will walk outside and look at it. I won't rely on edited You Tube clips as my sole source of information.

That doesn't mean that some of the videos on You Tube don't actually show a blue sky, you made a faulty leap of logic there. But what would you do if there was a video showing a blue sky, and another showing a green sky? Just go with which ever one you found first?

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue