The hard feelings from their on-track feud in the final weeks of the 2009 campaign may have stretched into the offseason, but that didn't stop Brad Keselowski from sending rival Denny Hamlin a Christmas card. The message on the front was simple: Peace on earth. The personal note on the inside was laughable: "Your friend, Brad Keselowski."

"I didn't want to get wordy," Penske Racing's newest driver said with a wide, mischievous grin.

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Brad Keselowski had questions to answer as his skirmishes with Denny Hamlin escalated as the season prolonged.

• Dover wreck
• Dover reaction
• Phoenix wreck
• Phoenix reaction
• Homestead wreck

And he wonders why he didn't get one back. It was another subtle needle, the under-the-skin type in that Keselowski seems to revel. He won a Sprint Cup race that featured a massive crash at the finish, and didn't even flinch. He became embroiled in a retaliatory rumble with a more successful, more experienced driver in the Nationwide Series, and never once backed down. He was labeled as too aggressive by some in NASCAR's premier series, and laughed it off. He ruffles feathers and tips over apple carts with unvarnished glee.

Yes, Keselowski has earned himself quite a reputation in his short time in the sport's national divisions. He knows it. He doesn't hide from it. In fact, he seems to enjoy it, a fact that likely peeves his antagonists even more.

"There's a quiet amusement to it, yeah," he said. "You know, how do you put that? I enjoy the fun of pulling up behind somebody and knowing that guy has gone, 'Oh, not him.' I enjoy that part. That part is fun. I don't necessarily enjoy the media part of it, but I enjoy that factor. That part is fun. That's probably the best answer I can give you."

It's not an act. This is a guy who will admit, he got into his fair share of fights in middle school. This is a guy who said he won the first race in which he ever participated, and has carried a degree of confidence with him ever since.

"There's always been a part of me that, when I get in that competitive mood, just elevates as a personality to where, for lack of a better word, you just don't take no s**t," Keselowski said. "That's where I feel like I'm at. I feel like I've got a pretty good tolerance when I get out of the car, but once I get in there, I can get a little mean sometimes. That's what's fun to me. It's bringing out that part of you that brings out that edginess and that drive. That's why I love racing, because it has that ability to bring that out of me. That's the best way I can explain it."

And yet, there were times when that edginess was difficult to find. Although Keselowski may come from a well-known racing family -- father Bob, uncle Ron, and brother Brian have all had stints in NASCAR -- Brad did his time in lean, under-funded vehicles. Twice in his NASCAR career he's had rides disappear from underneath him because of sponsorship woes. He was jumping from one team to another, taking a variety of fill-in jobs until Dale Earnhardt Jr. gave him what amounted to a three-race tryout in the No. 88 Nationwide car in 2007. Anyone meeting him about that time would have found Keselowski to be somewhat quiet, and far removed from the rambunctious driver who will take the reins of the No. 12 car this year.

He had been beaten down by circumstances. But the real Keselowski -- the fiery one who went fender-to-fender with Hamlin last year -- was still in there, waiting for the right time to re-emerge.

"When I first started my racing career, the first race I ran, I won. And when I was going through that process as just a young kid who didn't know anything about driving, I had the same attitude I have now. Had the same confidence. I got into a period where the money ran out. I was still winning, but the money ran out. Where do you go from there? I started to take the under-funded rides, the rides that never had a shot at winning. Not a chance in hell at winning. I took them, and it took that part of me out. It took that confidence and enthusiasm away, and I lost that for about three or four years," he said.

"During that time span, it changed me as a person. I feel like once I started winning again, I feel like I've returned to myself. I don't feel like I've changed. I finally got the confidence back, finally got some swagger back in my step. I don't feel like I've changed, but I've returned, in a way. I feel that with confidence, I can do anything in these race cars. With confidence I can work with these teams, I can work with a company like Penske, and the sky's the limit. We can do anything. So I'm certainly not looking to change that."

But can he bring that same, often-antagonistic personality with him to Penske, which from the outside seems a rather buttoned-down organization where most everyone is clean-shaven and everybody wears the same starched white shirts? The car owner doesn't think that will be a problem. After all, this is an organization that used to feature Rusty Wallace and currently fields cars for Kurt Busch, two drivers who have done their share of rabble-rousing in their time.

"I think he's just exactly what we want," Roger Penske said of Keselowski. "I think he knows how to drive. I'd rather be trying to grab his belt than kicking him in the rear end. I think he'll do fine. He certainly has a great reputation with the fans. His reputation within our shop is outstanding. He's really been very proactive there to try and build a relationship. Sure, there's a little bit with Denny Hamlin. But we've seen that. Look at [Juan] Montoya and [Tony] Stewart. ... You need a little bit of that, don't you?"

Busch, who's had ample experience in this area, said Keselowski's penchant for stirring the pot shouldn't be a problem if his car sponsors are all OK with it going in. After that, he added, the most important thing is "staying true to yourself." Keselowski doesn't sound like he'll have a problem with that, despite his new surroundings.

"I think you can be anything you want to be as long as you're willing to pay the consequences," he said. "And from what I've seen from the team, from the company, is, they don't mind that as long as you're not being a jerk about it. It's one thing to race hard. It's another thing to get out of the car and curse out everybody on the team and things like that. I don't feel like I do that. I'm not going to say I don't have verbal diarrhea every once in a while. But as far as the team and their relationship, I feel like we're all pretty supportive of each other. I think my team enjoys seeing the aggression on the race track."

And there are always new potential targets for that aggression. One could be Kyle Busch, who during a recent media tour stop at Joe Gibbs Racing said he had heard that Keselowski hadn't bothered to talk much with his older brother Kurt. Keselowski countered that he and his new teammate have talked quite a bit, including two or three meetings held during one week alone.

"Kurt's trying to keep all our conversations secret, because we're going to go beat them," Keselowski said. The mischievous smile comes out again. Let the rabble-rousing begin.