I stumbled across this tantalizing bit of info about a project that Mann almost got involved with, an adaptation of William Gibson's second Cyberpunk novel, Count Zero.
At the time of production of the Johnny Mnemonic movie (ugh), Gibson sold the rights to most of his remaining novels, and one of these was Count Zero which was sold to Atlas Entertainment. The name change to The Zen Differential.
I did some digging and found out that John Lloyd Parry produced a script (he only has 1 credit on the IMDB), dated December 11th, 1995 and titled The Zen Differential. Following Heat, Mann was briefly linked with an attempt to adapt Gibson's novel Count Zero into a film. Mann was to direct and the film was to be produced by Kathryn Sommer and Chuck Roven. In the meantime, it has undergone several revisions by Shawn Slovo. The new script more closely follows the original storyline in the novel, and the title has been reversed to Count Zero. Currently the project is on hold at Warner Brothers' Studios.
After Neuromancer, Count Zero is probably my fave Gibson novel and after re-reading the first chapter again, I could totally see Mann directing this:
They set a slamhound on Turner's trail in New Delhi, slotted it to his pheromones and the color of his hair. It caught up with him on a street called Chandni Chauk and came scrambling for his rented BMW through a forest of bare brown legs and pedicab tires. Its core was a kilogram of recrystallized hexogene and flaked TNT.
He didn't see it coming ...
The attention to details, in particular the fashion-sense of his characters, is right up Mann's alley. In fact, some parts of the Miami Vice film (when they were in South America), made me think of some of the imagery Gibson describes in the first chapter of Zero.
I think that Mann ever decided to branch out into SF, this would be an ideal choice. It's a shame nothing ever came of this project. Does anyone know where I can track down a copy of this script? I'd love to read it...