Romney visited the track for a few hours before the scheduled start of the Daytona 500. He spoke briefly at the pre-race drivers' meeting and spent time walking around the garage and pit areas, shaking hands and taking photographs with fans.
Asked if he would be rooting for something bad to happen to the No. 26 car being sponsored by Republican rival Rick Santorum's campaign, Romney laughed, saying, "I hope all the cars have a good race."
"I just hope they all have a good race," Romney said.
Romney was introduced at the drivers' meeting and received hearty applause from drivers, team members and other VIPs.
"This combines a couple of things I like best, cars and sports," Romney told the group. "I appreciate the spirit of the men and women that are driving today. This is a chance to really look at some of the determination and great qualities of the human spirit. This is quintessentially American. I love what you're doing, happy to be here today, wish you all the very best and God bless this great nation of ours."
He delivered similar remarks to the fans, briefly speaking on a stage in the infield during driver introductions.
Fans yelled messages of support as Romney roamed around the infield, although at least one shouted "Santorum!"
Asked if taking time to appear at Daytona was an indication of his level of confidence going into Tuesday's primary in Michigan, Romney said it wasn't.
"No, it's a sign of a guy who loves cars," Romney said. "And this has always been a place where American cars have shined. And a long history from Daytona being connected with Detroit, with Detroit cars, and with the spirit of America."
Romney was at Daytona last year and said he also has been to the track in New Hampshire. When asked how closely he follows the sport, Romney acknowledged that he isn't necessarily a hard-core fan but has a working knowledge of the sport and friendships with some of the people involved in racing.
"Not as closely as some of the most ardent fans," he said. "But I have some great friends that are NASCAR team owners."
Romney said he has visited team owner Richard Childress' facilities and came away impressed by the technology.
"I go back to the 1960s, back then when you had guys like Bobby Allison driving, they were driving stock cars," Romney said. "Maybe they'd taken out the passenger seat and the back seat so they can put in a restraint system and a fire extinguisher. But now these cars really are built from the ground up entirely by the teams themselves."
Romney spent time talking to team co-owners Chip Ganassi and Felix Sabates, who took Romney over to meet driver Jamie McMurray on pit lane.
Driver Brian Vickers walked along with Romney's entourage for most of the morning and spent time talking to Romney.
"I'm a supporter of his, and I like his policies," said Vickers, who is not in the Daytona 500 field.
With a campaign event scheduled in Michigan later Sunday, Romney wasn't scheduled to stay for the race -- just as well, because it was postponed until Monday by rain.
Earlier Sunday, Santorum discussed his campaign's sponsorship of the No. 26 team and driver Tony Raines on ABC's "This Week."
"I talked to (Raines) about a strategy," Santorum said on the show. "I recommended he stay back in the pack, you know, hang back there until the right time, and then bolt to the front when it really counts. So let's watch. I'm hoping that for the first, you know, maybe 300, 400 miles, he's sitting way, way back, letting all the other folks crash and burn, and then sneak up at the end and win this thing."