I would not trust these clowns to work on my car.
Just the fact they are stupid enough to push a car like that on a dyno is indicaiotn they are not the gretaest thinkers in the world.
The stress and strain that thise tie downs are being subjected to as they jerk the car through the gears is immense.
The only reason I see them doign this is to not have to deal with the poor aerodynamics of the brick that is the Mustang
I am guessing one of these days we will see the video of one of the cars they are tuning breaking free from the dyno and killing a half dozen people..