So, if you read through all the posts here and take notes, you will notice one pattern: they ALL do this.
07, 12 - does not matter.
2nd pattern is - it's very intermittent.
3rd pattern is - no one reported any major damage from it.
I saw the video mentioned here. It's definite low oil pressure shudder. I doubt it has anything to do with what we experience. I observed same on my son's Infinity, and it sounded like engine will fall apart. We did oil change and that was it.
Hence, let me return back to my original statement. I believe, it's something that is pertinent to how PSD works. You have to have all gears in it, and all pistons and moving engine parts, aligned all together just so, to have nice and clean startup. Does it happen perfectly every time - I doubt.
I could, possibly, blame it on low oil pressure, but neither my, nor White's cars ever run low on oil, we are anal in that respect. Blaming it on engine mounts is sort of, well, you know,
considering it happens on 12 models as well.
Btw, you ever looked at those engine mounts? You saw THE SIZE of them? They are designed for thousands of shut downs and start ups a day.