There's an electric 4 way joystick on the side of each seat but they also have levers so you can do everything manually anyway.
Here is a photo of B7. The loom and sockets look exactly the same although on B8 the box is square, not rectangular but this is irrelevant. I've had only Yellow and Black ,where Black is a seat belt sensor and yellow is an air bag control. This leaves me with two extra plugs Red - for position and lumbar support and Green for the heaters. I can buy a control unit for £ 35-50 but doesn't bother me because can always sell mine after that. The question is if somebody sells the actual harness so I can plug the control to the seat plug ? And would I need to do any additional coding, although common sense tells me that it's just an on and off switch so maybe no ? Maybe my best bet would be to contact a breaker and ask for a price of the control unit plus the harness ?