A scene was shot in which Illeana drives back to her house with the old pick-up and a branch from a tree falls and breaks the windshield. It took several takes to get the shot, and apparently destroyed the last remaining windshields for the pick-up available anywhere in North America at the time. The scene was not used.
The source novel's character equivalent to Illeana is James Costa, a British museum curator. Martin Asher's analog is Martin Arkenhout, a native of Holland. The prime settings of the novel are England and Portugal.
Illeana (Jolie) almost always conducts a search with her trigger finger wrapped around the grip. The trigger finger moves to straight along the gun, but never seems to be at least in the trigger guard.