What is the ISO insurance symbol for a 2004 Cadillac Escalade?

There isn't a single ISO insurance symbol for a 2004 Cadillac Escalade (or any specific vehicle). ISO symbols are used to categorize *types* of vehicles, not specific makes, models, or years. The insurance company uses the vehicle's information (year, make, model) to determine the appropriate rating class and associated risk, which then influences the premium. The ISO symbol would be part of the internal coding used by the insurer, not something readily available to the public for a specific vehicle.