heated seats???

[simonc]

im looking at two audi a3's, both brand new shape one has 99k and the other 85k. Theres not much between the two both same spec but only one has heated seats. They are both cloth interiors and i will be putting a heated leather interior in, will these heated leathers work in the car that doesnt have heated seats already fitted, obviously id need to buy the switch but would the wiring be there???

thanks