Have you spoken to your dealer?
Is it a popular model/colour/engine size that the dealer might be able to sell on to another customer, or perhaps another dealer might be looking for one.
I would tell the Dealer sooner rather than later, they can then check to see if there is an order for the same car further up the pipeline that they can cancel.
Bear in mind, the dealer will have to pay the importer for that car in 30 or 60 days or whatever their terms are and they will be stuck with trying to offload it if it is not something that may appeal to the masses.