They have agreed to replace the car, but I have had to wait for the car to arrive due to the waiting list (I think I skipped a fair bit of it, still).
I'm getting a like-for-like replacement next week, and they told me to look at the accessories booklet and choose what I wanted (within reason).
I went for the parking sensors, as the car isn't terribly easy to park, and also the coaxial speaker upgrades, the tweeter upgrades, the speaker rings, and the bassworks sub+amp upgrade. Over £1,000 worth of kit all in.
They wouldn't stretch to the satnav, and this would have been extra time on top of the wait for the replacement.
Ended up getting Steve Oliver to sort this out personally!