At the beginning of the movie, when Denny comes home, a puddle of urine is in front of Enzo. However, as the movie nears to an end and at that point in time, the puddle of urine is between the Enzo's legs, not in front of him.
Denny tosses to Enzo a piece of food he just removed from the oven. This would likely be too hot for a dog... or anyone.
The ambulance has no unit ID number on the back.
At the end of the film when the formula cars are driving around Mugello they are driving around the wrong way, you can see the pit entry on the left hand side of the track.
It's unrealistic that when Eve takes their daughter to go stay with her parents, that for at least two days she left Enzo (dog) alone and did not tell Denny about any of this.
After Denny leaves for a race, Eve and Enzo go for a walk in the forest. While Zoey is in school.