A test programme of the new car was already well underway, with several drivers getting to sample a version of the car.
Separate testing sessions conducted at different tracks since October 2019 by Austin Dillon, Joey Logano, Erik Jones and most recently William Byron at Auto Club Speedway meant the car was nearing its final stages of design.
Probst called the version run by Byron at Auto Club “99 per cent” the version the series plans on introducing, though it will now have to wait longer to break cover.
Several features of the cars will be different on the new-gen car, with NASCAR moving to single lug nut centre-locking 18-inch wheels, as well as larger brakes, a shorter rear spoiler, redesigned skirts and for the first time in the series’ history, a rear diffuser.
Those changes are meant to replicate road-going versions of the cars available to the public offered by manufacturers Ford, Toyota and Chevrolet and offer a chance for smaller teams to take on bigger organisations.