No, vehicles are generally *not* wired for all possible options at the factory. While some basic wiring harnesses might have extra capacity or unused connectors for future expansion, it's far too costly and complex to wire a car for every conceivable option. The wiring harness is tailored to the specific options ordered for that particular vehicle.
For example, a car without a sunroof won't have the wiring for a sunroof motor, control module, and associated safety features. Similarly, a car without heated seats will lack the wiring for the seat heaters and their controls. Adding these options later is often significantly more expensive and difficult than having them installed at the factory.
