I specifically do Not know what he means by, "floor PAN". The FLOOR of a car is the FLOOR of a car. A FLOOR description is easily understood. FLOOR or FLOOR BOARD is specific all by itself. The "PAN"? I am familiar with the OIL "PAN" at the bottom of a car. Maybe the oil pan had a bullet hole in it?
Getting into a possible bullet hole in the floor/oil pan of the JFK Limo then leads to the discussion of a possible missed shot. A missed shot striking the street and ricocheting underneath the car and Upward into the oil pan.
Striking the tarmac directly would result in the slug annihilating into small bits. And a big "hole" in the tarmac.
There would be no ricochet offa tarmac at that angle. No hole in the limo. No brass half jackets in the limo. No splatter hitting JFK on the head.
No, the slug ricocheted offa the overhead signal arm. At about pseudo-Z105. And the photo of the hole in the floor is true.
The remnant slug might then have hit the driveshaft &/or tarmac.
The floor carpet (& hole in carpet) might still exist, even tho the guy who removed/replaced it in 1963 said that he destroyed the carpet.