Wife Ashley Judd's devotion was never more public than when Franchitti won his first of three Indianapolis 500s on a rain-soaked day in 2007 as she danced and ran down the raceway to celebrate.
"When he was introduced, or got a good pole position she yelled and waved her hands in the air and was there to support him in a big way," a source at another track, Watkins Glen International raceway in New York, tells PEOPLE. "He is not that outgoing but it seemed cute and like a nice thing for a high-profile actress to be so there for her husband."
So for some in their racing circle the news of their split this week after nearly a dozen years of marriage came as a shock. "It looked like they were pretty happy," says another source.
Others, however, had seen indications of tension between the two stars. In a joint announcement, Judd, 44, and Franchitti, 39, said they had "mutually decided" to end their marriage but would "continue to cherish" their relationship.
"They can be having a drink or dinner and all of a sudden sparks will fly, and they will be fighting over something that was said in their group of friends," another racing source says. "Then it would stop and everything was fine between them."
They had been the ultimate glamour couple, the 2001 marriage of beautiful actress and dashing Scottish driver bringing together the world's of Hollywood and sports.
They often traveled together and shared in each other's successes. In 2012 Franchitti basked in his third Indy 500 victory by posing for photos with Judd and their two cockapoos, Buttermilk and Shug.
But those close to them saw another side. One night they were with a group of people at Tanino’s, an upscale Italian restaurant in Horseheads, N.Y., not far from Watkins Glen International, where Franchitti, 39, races each year.
"The place was packed and Ashley was kissing Dario, playing with his face and trying to get him to concentrate his attention on her instead of the rest of the group," a source tells PEOPLE. "It was cute at first but went on and on, you could tell he was uncomfortable with the public [affection]."