Keep us posted on how you get on. If they confirm the car hasn't got b&o I doubt they'll retrofit it as Audi don't do retrofits. Your only option would be to reject the vehicle.
Glad there's no leak. Be careful not to overfill the engine with oil.
Let's hope it's just the service light. If dipstick is normal, but onboard computer saying it's low then most likely the level sensor is faulty.
I think it was standard with the tech pack. My advice is to ask the dealer selling it. If you want a built in sat nav you'll.wat a car that already has it as activating it can only be done by Audi at a cost of £500-600 at least
What we've seen when people have fitted different seats is if they've tampered either the airbag wires it causes the airbag warning light to illuminate. So the easiest way is to remove the airbags from your current seats and fit them to the new seats.
This advice obviously comes a little late for you.