Can you trust a dealership to apply a ceramic coating?
It depends on the dealership. Some will have an in-house detailer with the proper equipment and facilities, who takes pride in his work. Some call in a professional detailing company. Others will subcontract to an agency who hire people on minimum wage and zero-hours contracts -- tomorrow they might be packing fruit in a warehouse. Some dealerships may use a combination of both.
For the dealership, a ceramic coating is an up-sell. If the salesman can get you to buy some kind of coating, he gets the commission, but there is a likelihood the guy that is supposed to apply it gets nothing. The salesman might even give you a ceramic coating for free as a sweetener, as he is getting a bigger commission on the sale of the car. Either way, the salesman has a big incentive to sell it to you, but the detailer/valeter/cleaner may have no incentive to apply it properly.
It is sometimes the case that a contractor will turn up once a week and have to wax and polish dozens of cars. Sometimes the agents that supply the labour make the contractors buy their own products, such as wax. As they may only be getting a couple of pounds per car, they may well use the cheapest wax they can get and only do down them to door handles.
Over the years, we have seen many problems with cars that had polymer and ceramic coatings applied at a dealership. Sometimes coatings were not applied at all. Sometimes it was only applied to the upper surfaces of the car, and sometimes it was applied over the top of wax, and so wasn't bonded to the paintwork. We should also mention that the vast majority of cars that comes to us for coating, direct from the showroom, have scratches and wash marks that require machine polishing before a coating can be applied.
The larger part of the cost of ceramic coating a car is in the man hours that go into preparation of the paintwork before application -- a great way to cut costs and increase profits, is to just not bother to do the prep.
With all that said, some dealerships have fantastic guys, or teams of guys who are highly professional. If you are offered a ceramic coating at a dealership, we recommend that you ask to see their detailing bay and to meet the detailer. Ceramic coatings are less about the product and more about skilled application.