I think I have noticed it before but it was very faint but haven't seen it again, I'll have to try it again.
I've done that, can't see a thing and nothing hits the ground. It's weird. No burning oil smell, no wetness except around the oil pan which I'm pretty sure it's the gasket there. It's not soaked or anything either, just a little. My engine is just a thirsty mother f'er.