You know, so mad that he would go out and retaliate the way Busch and others have done when they believe another driver has wronged them.
"I don't know," Kahne said last week in his usual soft tone. "It might happen."
Maybe it's time.
Maybe the only way for Kahne to send the message to Busch and others that he simply won't tolerate being wrecked -- even if it's unintentional -- is to send the Joe Gibbs Racing driver into a spin.
It probably won't happen, although Saturday night's Sprint All-Star Race is the perfect setting since no points are involved. It's not in Kahne's makeup to retaliate, at least in such an obvious way as Busch did to Ron Hornaday Jr. in the Camping World Truck Series two years ago at Texas or the way Jeff Gordon did to Clint Bowyer last year at Phoenix.
His way of sending a message is more subtle, like the not-so-friendly tap he gave to Mark Martin after Martin crashed him at Richmond.
"At Richmond, I was really mad," Kahne said.
Kahne shows his anger the way the Mona Lisa shows she's happy: You have to look hard to see it.
But you could hear it Saturday night in the sarcastic tone he used to describe how Busch "screwed up" and what likely will happen this week.
"I imagine he will call me again tomorrow and say he's sorry," said Kahne, referring to the apology he got after Talladega.
Busch knows he messed up, just as he knew he did at Daytona and Talladega. You could hear it in his voice over his in-car radio even if you didn't get to hear it after the race. He left Darlington Raceway without talking to media after a late tire issue left him with a sixth-place finish in a race he dominated.
Kahne stayed and talked after a 17th-place finish that could have been a win.
Maybe he is reaching a boiling point.
"Well, he needs to quit. I mean he's got to just race me," Kahne said of Busch, who's not known as a dirty driver.
But when asked how he would race Busch moving forward, Kahne gave the answer you would expect.
"I will race him the way I've always raced him, the way I have always raced everybody," he said. "You try not to screw up and take people out when you are around them."
Maybe he needs to make an exception. Like in school, sometimes you have to stand up to the bully to let them and others know they can't walk all over you without consequences.
Were it not for Busch, as I wrote last week when Kahne told of the Talladega apology, Kahne would be near the points lead instead of in sixth. He might be the one with a series-best three wins instead of Busch's teammate Matt Kenseth.
Maybe this will work itself out. Maybe Busch will pull over and let Kahne pass the rest of the season when he knows Kahne has a faster car.
But that's not in Busch's makeup.
So maybe it's time for Kahne to send a message he's not to be messed with, to let people know he's a serious championship contender.
The All-Star Race would be the perfect place.