If it was in the ad, then it is what you responded to. If you were not there to accept delivery, then it is a defect you discovered as soon as delivery was effectuated.
In California bait and switch tactics, particularly on high ticket items, violates the Unfair Competition Law. B&PC 17500 as it constitutes false advertising. And it would also violate Civ. Code 1750, the Consumer Legal Remedies Act.
I suggest that you return the vehicle to the dealership with a copy of the original ad. Their remedy would be to replace it with a vehicle that has the amenities they advertised. Or they will spend quite more trying to install what should've been there from the factory. It is much more expensive to install aftermarket leather and navigation than if it rolled off the assembly line that way.
And, who knows what kind of aftermarket you will get.
This is a public forum. Any questions or answers published here should not be construed as the giving or receiving of legal advice or the formation of any attorney-client relationship. You should consult with a competent attorney in the jurisdiction where your legal issues are pending and get good, solid legal advice. This being a public forum, those answers you do read are merely given for informational purposes only.