Do not get mad, but if you clearly watch the video, the entire vehicle is shaking. Look at the passenger seat belt, its moving like you are going over bumps at 40 mph.
And have you owned a extended cab truck with bench seats from the early 90's? or a Pre 1993 S-10 Blazer 2 door, the seats moved that much.
Let everyone watch the video again and you can see the passenger seat belt shaking pretty good and actually at one point the camera is going up and down. I do not know if you had the camera mounted to the door of the Runner with the window down, but whatever the camera was attatched too, it was moving too.
And yes, i do realize there is something wrong with the seat, it should not move that much. Apparently the dealer does not know what they are doing to fix it.
It that was my vehicle, would of done like I said before. Take apart the seat, find out where it is loose and start welding.
Did you even try to have the dealer or during arbitration try to have them install power leather seats since those do not have the problem?
I am sure Toyota would of did that since it would of saved them money.