Not much is known about Zil, but it has been revealed that early during the development of Cars 2, Zil was conceived as the main antagonist of the film, being behind the Lemons' plot to turn the entire world against alternative fuels and make money out of it. From what can be seen in concept art, Zil's design was based on the 1951 ZIL 112/1, a race car made in the Soviet Union that performed poorly, which means that Zil was intended to be Russian.
An alternate opening for the film, storyboarded back when Zil was set to be the main antagonist, has Leland Turbo (a character who is killed off early on the finished film albeit offscreen) being chased by the Lemons while trying to contact Finn McMissile until he hides in a dumpster. However, just as he believes that he is safe, Leland discovers the corpses of many other cars before the Lemons appear and a crane grabs him to then toss him into a car compactor. As Leland gets his tires busted, Zil appears from the shadows and asks Leland where is Finn McMissile, but Leland refuses to tell him, vowing that Finn would stop him. Unmoved, Zil says that they will see it before Leland is fatally crushed and compacted.
However, Zil ultimately proved to not be popular among the producers, who instead preferred the character of Sir Miles Axlerod. As a result, the filmmakers opted to drop Zil from the film and use Axlerod instead as the main antagonist, whereas the Russian character element from Zil was given to Professor Zündapp, the film's central antagonist.
- Zil is very similar to Xerek, the originally intended main antagonist of The Incredibles: both were initially conceived as the main antagonists of their films but got replaced by another villain who proved to be more popular to the crew (Sir Miles Axlerod in Zil's case, Syndrome in Xerek's case).
- For a while, Zil was speculated to be recycled for appearing in Cars 3 as a minor character. However, these rumors turned out to be wrong, as Zil didn't appear in the finished film at all.