"The Spy Who Loved Me" and "Quantum of Solace" stories are both attempts by Fleming to depart from the usual Bond formula. "Spy" has a female narrator, the only story in the Bond canon that is told from a first-person narration. "Quantum" was an attempt by Fleming to tell a story in a pastiche of his literary idol Somerset Maugham. There was really no reason for it to be a Bond story, but perhaps Fleming felt that it would sell better if Bond appeared in it. That considered, I'm surprised Bond didn't put in an appearance in "Chitty Chitty Bang Bang".