The cars, which trade in the sleek slopes of the old vehicles for a taller and wider look, are scheduled to debut at Tennessee's Bristol Motor Speedway, appear in 16 of the 32 Nextel Cup races yet to be driven this season and be completely phased in to NASCAR by 2009, The Washington Post reported Thursday.
Two-time champion Tony Stewart called the new car "a flying brick."
"This car doesn't aesthetically appeal to most people's eyes," driver Kurt Busch told the Post. "Yet we have to give it a chance and let it race and see it out on the racetracks and see what it can do from the inside out."
NASCAR officials claim the car will put the "racing" back in stock-car racing.
"Sure there's unknowns," John Darby, NASCAR's Nextel Cup series director, said in the Post report. "When you go to a dealership and you buy a new car, you drive it home; you don't know how it's even going to get you there. Part of the excitement of having that new car is taking that maiden voyage."