Dale Earnhardt Jr. didn't have the day he or his team was looking for in Fontana, as he finished a disappointing 32nd after breaking an axle - a problem he said was part of the same issue that felled Jimmie Johnson at Daytona.
Earnhardt Jr. said the team believes it was faulty material in the axle that was responsible for the failure.
"They've got to go through a batch and find out what's going on," he said. "... Something's going on there where we're chewing that stuff up and tearing it up."
Despite the setback, Earnhardt Jr. said he was "actually moving forward better than the other guys around us" who had been running up front all day and gotten the wave-around after being pinned on pit road.
Earnhardt Jr. said he felt pretty good despite a "tough day," but added, "I mean, we weren't that great - I'm not going to be foolish."
But when a reporter asked Earnhardt Jr. why he struggled so much in comparison to his teammates, and the sport's most popular driver became frustrated.
"I can't build the cars, you know?" he said. "What do you want me to do? I just drive."