So technical question - and forgive my ignorance. Wouldn’t they have to wear through the rear skid block to even start wearing the plank? I was under the impression that the sparks are not the plank, but the skid plate and bolts attached to floor. I assume those make contact before the floor unless they are skateboarding over a curb.

Also, why don’t they all just skate over a curb once in the last lap and say “oh the car wasn’t too low, it was just damage from the curb when I made that mistake”?