With my tile boxes sitting in the sun upon install (Expanded) I installed the leading edge of the ramp pieces within a 1/8 - 1/4 inch or so of touching the door with it closed.
So the real foot tiles should start 3.5 inches from the garage door seal? In the racedeck video it seemed like they started the 12 inch wide tiles not the 3 inch ramps around 1/2 inches from the metal guide rails.