Typically with two to go a cone will be put on the backstretch and the cars choose their lane. So everyone is 2x2 and has chosen their lane when they get the one to go. At that point the cone is retrieved by the track worker. This is typically how it's done on short tracks with cars doing 30mph under caution and with 20 cars on tracks...now with a 40 car field, a caution pace in the 50-70mph range on the larger tracks, and wave-around cars going at green-flag speeds...NASCAR would likely have to modify the procedure. My best guess is that there would be a painted box in the middle of the backstretch, similar to the painted box on pit road that acts as the commitment cone on short tracks where placing a literal cone is not feasible. That way we don't have a track worker out on the track while cars are taking the wave-around with one to go and driving at race-pace. NASCAR won't give the one-to-go signal until all track support vehicles are tucked away behind a wall. Unlike short tracks where I've seen many pick-up trucks race back to their safe spot as the field is taking the green
. So no, there's won't be a track working running across the backstretch to retrieve a cone as the field takes the green.