I have a Superb Business, 2l diesel, which has blanking plates where the heated seat buttons should be (on the dashboard). Does this mean that the seats are wired, and just need switches fitting ? I have reached under the front seats and there seems to be a thick cable, which on the drivers side may be for the "Set Seat Position", but the passenger seat also has this cable. Any help would be appreciated.

No, VAG do not fit hardware that is not ordered, so no looms or heated seat elements will be fitted. 

If it was a selectable option on that model the wiring may be in the loom the car was built with, the element won't be.  The wiring you can see will be for seat belt sensors and airbag.

 

The element is part of the seat cover on VAG cars

thanks guys..saves me a lot of messing about