According to Slate's examination of fact vs. fiction in "Ford vs. Ferrari," a main emphasis was placed on the bad blood between the Ford Motor Company's Henry Ford II and Ferrari's Enzo Ferrari — which was nearly as bad in real life as on screen.
The plot of "Ford vs. Ferrari" kicks off when Ford attempts to acquire the Ferrari company, but is rejected and insulted by Ferrari. In real life, Enzo Ferrari did in fact insult Ford's owners personally, apparently calling them "worthless sons of w***es," and Ford II a "pig-headed boss." Ferrari's lawyer, Franco Gozzi, reportedly called it "a tirade that I had never seen or heard before in my entire life and have not done so since" (via Slate).
For Ford's part, his reported response to the slight was more graceful in real life than the movie, in which he says Ford will bury Ferrari "100 feet under the finish line at Le Mans." In reality, Ford reportedly said, "All right, we'll beat his ass. We're going to race him."
Additionally, while Iacocca approaches Shelby to assist Ford with building a race car capable of beating Ferrari in the movie, in real life, Shelby approached Ford. According to the book "Ford vs. Ferrari" is based on, titled "Go Like Hell: Ford, Ferrari, and Their Battle for Speed and Glory at Le Mans," Shelby pitched Iaccoca on the project and asked for $25,000 to build two cars.