11. Using the measurements taken from beneath the car, measure from the edge of the floorpan to the base of the seat riser and draw a vertical line. On DSE’s Mustang, this distance measured 11.125 inches and established the centerline location of the subframe connectors. Line the supplied seat riser cutout template up to the vertical line, and trace the cutout area. Next, cut out the seat riser section with a cutoff wheel.