I added 4" to the second piece (photos to come), and I've now glued up another 6" (sections 11-13) for a total of 4'-6" of the front:
The gluing is slower now because the sections hang off my table too far (as you can see) -- I need to make a table the is ~6'x6' for the middle part of the car. All 4 battery bays have started -- the outer 2 extend just 2" forward, and the center 2 extend 6" forward.