MARTINSVILLE, Va. -- Robin Pemberton, NASCAR's vice president for competition, gave the Car of Tomorrow an A-minus for its performance in last week's debut at Bristol Motor Speedway.
Nextel Series director John Darby gave it a B.
At least they left room for improvement.
"It's pretty childish to complain about something in a way that a lot of these guys are complaining about it. ... Just some of them need to grow up and just figure out how to be constructive and be men about it and not act like a little boy."
-- Kevin Harvick
The general consensus in the garage is there needs to be improvements after failed exhaust systems released carbon monoxide into the cockpit of some cars, foam melted the right door panels and produced fumes in others, and there were problems with the balance and height.
The exhaust system was addressed first because of the potential dangers that could come from it. Darby said most teams that had that problem corrected it by using thicker material in the tailpipe.
Darby said the height tolerance for post-race inspection will be relaxed from a quarter of an inch to half an inch on the rear end while NASCAR determines just how much the cars settle during an event.
He added that the minimum weight allowance on the right side of the car will be adjusted from 1,650 pounds to 1,700 pounds.
"We understand we have to have a minimum going down the road to protect the overall height of the entire car, but where we're at right now is not knowing where the teams need it, not knowing where we need it," Darby said on Friday at Martinsville Speedway.
"We started with a procedure with very, very small minimums and very quickly understand that those need to be expanded to allow the teams to have an operating range they can live with during the race."
But overall Darby and Pemberton considered Bristol a success. They don't think the car "sucks" as Kyle Busch said after winning a week ago.
Kevin Harvick said it's time for drivers to stop criticizing and work constructively to make the car better.
"The car is what it is," he said. "It's pretty childish to complain about something in a way that a lot of these guys are complaining about it. This is our sport. And in order to keep our sport going forward we all need to be constructive about new things.
"Just some of them need to grow up and just figure out how to be constructive and be men about it and not act like a little boy."
There are some things drivers actually like about the new car, such as the way the front and back bumpers match up to prevent drivers from getting the front bumper under the rear bumper of another car to spin it out.
"You can just ram people," Harvick said. "It's great. It's going to make for a good bump draft on every track."
Busch isn't so sure.
"Ever watch Legends car racing at Charlotte?" he asked. "Ever seen anybody lay a bumper and knock somebody up out of the way, just push them? You lay into their bumper and just push them.
"You can use the guy in front of you for your brake. Instead of being scared of lifting the guy and spinning him out, now you can just lay your bumper on him and push him out of the way and get by him."
Busch said in the old cars you knew whether somebody did that on purpose.
"Now you're never going to know if it's an accident or on purpose," he said. "We're going to see a lot more lies. How about that?"
Darby and Pemberton brushed aside concerns that the splitter of a trailing car cut the left rear tire of the car in front, saying that was no more significant than fenders cutting tires.
Busch's biggest concern with the splitter is it's too low.
"We're kind of limited and boxed in on what we can do on the front end," he said. "The splitter height has a lot to do with that.
"They want to make parity. They want to make everybody pretty equal, but we've got to get these things driving better first, give us a little bit bigger box to work in."
NASCAR officials understand there are going to be differences of opinion and perhaps misinformation as the COT moves forward.
Kenseth, for example, said the fumes from the burning foam in his car were toxic.
"I don't care what they say, whenever you make something man-made like foam and all that stuff, when that stuff melts and burns I know the fumes and smoke coming off that can't be good for you," he said.
Darby said the burning foam created cardon dioxide, not carbon monoxide, and that nobody was at risk.
Both Darby and Pemberton agree that the more time everybody spends with the car the better it will be, noting inspectors trimmed four hours off of that process from last week to this.
"A race is a race to us," Pemberton said. "I don't think that any of us will let one or two bad apples spoil what we think was a great achievement for a lot of teams, competitors, our engineers and anybody else that had anything o do with the success of this team in the first outing, or success of the car."
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org.