Even though Luca Pantoni's role in the book is brief, it's important: this guy is literally a lifesaver.
At first, his inclusion in the story seems like a throwaway. He comes over for dinner one night while Eve's alive, and then shows up almost at the end of everything, a year or so after Eve's death. His reappearance is like that of a sweater that was stuffed in the back of your closet that you forgot you owned: unexpected but enjoyable.
So he shows up out of the blue to see Denny, but then he also offers Denny a posh job test-driving Ferraris for rich Italian car owners who want to drive really fast in their free time.
That's like winning the lottery of racing-related jobs, and the fact that Luca shows up when he does is nothing short of magical. Which leaves us wondering, is Luca Pantoni even real?