I've got the earlier X Line version, they're well equipped as standard but might not have heated seats. Why have leather and no heaters? Germans, Pffftttttt.
With it still being under warranty just check the servicing has been done on time if relevant.
If you decide to buy it only use BMW washer fluid, if the washers fail, and they do, if it's non BMW washer fluid the sizeable bill will be all yours.
Check for even tyre wear and if a little out then it needs a 4 wheel BMW alignment at their expense.
Upt'North.