I have just bought 2008 ve calais and the previous owners did not have the sat nat option included when they bought the car. How do I now get that???
With the car being 9 years old, that system likely obsolete and the service no longer available, as you found out from the dealership. If it were possible, surely the dealership would have been happy to sell you what was needed to make it work.
This is the challenge with advanced technology in vehicles. Over time it becomes obsolete. Much like software, auto manufacturers have to decide at what point they stop supporting it.
I ran into this with using Ford Sync. After my car was a certain age, they stopped supporting it and I could no longer get updates. Obviously, each manufacturer will be different.