Jaguar XJ 2011 Satnav update - any cheap-ish options?

[WHoSaidThis]

Have a 2011 Jaguar XJ and want to update the satnav and not spend an arm and a leg...

Would buying a DVD off eBay be an option here? or these guys (mind you, not the cheapest) Navigation site

Any other options? thank you in advance

[vikingaero]

Search for Jag XJ satnav updates and there are lots of options for around £20. Not sure if they are legit discs/cards or if they work.