I bought a used car (120K miles) from a local dealer 4 weeks ago.
As I am not familiar with roads and directions (always! shame on me!),
I made it clear that the Sat Nav system on the car is very important,
and I needed them to update for me before I took the car.
Then the sales person suggested that they will replace the DVD disc (the map data) after several days.
And they wrote it (says "sat nav disc to follow version xx on date xxx") on the sales invoice.
And I paid full amount (£5K+) and drove the car away, and
made several hundreds of travel, then