Hi mpabian. Yes, this is the real story. It is not a matter of "...dealer add-ons "aren't allowed" with plan pricing...". It is a case of Dealer add-ons are not included in AZXD-Plan pricing, or given any sort of AZXD-Plan pricing discounts.
Therefore, since they are not part of any AZXD-Plan discounts, those add-ons are items which the customer must price negotiate separately with the Dealer, and/or refuse completely.
So Dealer add-ons can be included in the contract, but they do not have any Plan price protection and must be negotiated between the customer and Dealer
In your case (and in reality, everyone's case), you/we should stipulate in our purchase contract that no additional add-ons are to be included in the purcahse and will be refused.
It is not too late to do so. Stop by your Dealership and get it in writing that you do not want any Dealer add-ons. Also send emails and texts stating so. In that way, you will have a long paper trail.
Concerning the Dealership refusing to sell the vehicle to you? Well, the truth is any Dealer can do that at any time with any vehicle. But that is a rare occurrence.
Get it in writing from your Salesperson that you do not want any Dealer add-ons, and that they will not add them.
Let us know how you make out and good luck.