How does Denny realize that Enzo embodies the spirit of a racecar driver?

Denny realizes that Enzo embodies the spirit of a racecar driver during a "hot lap" in his racecar because this experience exemplifies the unique bond and understanding they share. In this moment, Denny is able to connect deeply with Enzo, who perceives and feels the intensity of racing from the passenger's seat. Enzo's observations and instincts reflect the qualities of a true racecar driver, such as focus, determination, and the drive to perform under pressure. This experience showcases how Enzo, despite being a dog, has an innate understanding of racing dynamics and the mindset required to excel, thus solidifying Denny's recognition of Enzo's spirit as akin to that of a racecar driver.