The XL2 is one of the models that originally had a very cut-down menu structure, but I thought that had been resolved or at least improved.
I could understand if it didn't have the "Drive on left or right" warning feature at all, but if it *is* warning you, then you would think there must be a set-up for it somewhere!
Unfortunately I don't have an example of that model to play with, I downloaded the reference guide (from
here), and I must admit I can't find any mention of the feature in it either (but TT manuals are notorious for not telling you everything!)
I suppose you could try a "Return to Factory Settings" (but you'll lose things you've saved like Favourites and Home location).
Otherwise, off the top of my head, maybe it's being clever and using one of the other settings to automatically choose the warning. I assume you've got a home location set in the UK and that you've got the language set to UK English?
It's a good question this one... I'll be interested to find out the eventual answer!