Check the fit of the new floor under the car, seeing how flush the pan is sitting on the framerails. Is it firmly up against the forward-facing tabs at the ends of the rails? Our pan didn’t sit flat. We put some weight on that area, and that was enough to settle the pan flush against the rails. Next, a line was scribed around each rail and the floorpan was removed from the car. We drilled 5⁄16-inch holes, 3 inches apart and 3⁄8-inch inboard and around the entire parameter of the new floor. The holes were ground with a right-angle sander, removing any burrs that would interfere with the floor’s fit.