If you have an XR and want a locking sat nav, you can buy all the parts from BMW for around £40, then don't have to worry about some toe rag nicking your nav when you park up somewhere.
The only slight issue (and why BMW didn't fit one in the factory), is that you have to rotate the whole unit up, whenever you want to remove the nav. This isn't a major issue, and is made easier if you have the emergency wallet key, as you won't have to rotate the unit as much.
If you want a list of part numbers, let me know, but here are some pictures of the parts, and the fitted product.
The only slight issue (and why BMW didn't fit one in the factory), is that you have to rotate the whole unit up, whenever you want to remove the nav. This isn't a major issue, and is made easier if you have the emergency wallet key, as you won't have to rotate the unit as much.
If you want a list of part numbers, let me know, but here are some pictures of the parts, and the fitted product.