The new 45 model will start being built from week 44 onwards so if you car is being built next Monday then it’s most likely you’ll still get the current 40 model. I phoned my dealer about my order and they said I can’t change the advance payment since it’s locked in and if I cancel then I’d go back to the end of the queue. I think my dealer is clueless tbh. It should just be an admin change for the reduced AP and shouldn’t affect the order with Audi.
Your dealer is being unhelpful and playing loose with the truth.
I ordered my car, a Mazda CX5, last December with delivery in late January. In January the AP dropped by £500 and I spoke to my dealer. As we spoke, he cancelled by Motobility order and placed a new one at the new AP. The order for the car remained the same.
The dealer does not keep the AP, that goes to MB so it is no difference to him what you pay.