After Ryan Gosling and Nicolas Winding Refn removed much of the Driver's dialogue, Bryan Cranston felt that his character, Shannon, should make up for the lack of talking in the film, and thus made Shannon a motormouth. Much of his dialogue is improvised.
In preparation for his role, Ryan Gosling restored the 1973 Chevy Malibu that his character uses in the film.
The unusual way Ryan Gosling's Driver holds the steering wheel, with thumbs crooked over the outside rather than hooked inside in a more 'normal' grip, is actually the common way stunt drivers hold the wheel to avoid broken thumbs during vehicle impacts.
The Driver and Irene actually say very little to each other, primarily because Ryan Gosling and Carey Mulligan felt that their scenes should be more focused on the mood and refused to say many of the scripted lines. Mulligan summarized making the film as "staring longingly at Ryan Gosling for hours each day."
Hugh Jackman was originally cast as the Driver in 2008, with Neil Marshall to direct. Jackman's studio Seed Productions was set to produce the film. Jackman and Marshall dropped out in 2010, and Seed was closed later that year. Ryan Gosling was cast instead, and, for the first time in his career, he was allowed to pick the director. Nicolas Winding Refn was his only choice.