What exactly was the reason they decided to go half price for you? Did they just feel like being nice guys? All of a sudden they aren't in the business of making money?
I said before that these stupid dealer-offered coatings are pure profit for the dealership. Obviously they'd rather get half your money than none of it. At half price, believe me they will still see profit from it. So how outrageous was the markup before
they offered half off? And what about the people who don't educate themselves on these practices, and actually pay full pop? How badly are they getting ripped off?
My advice is pass on what the dealership offers. Either have a professional detailer do the job CORRECTLY the first time or learn to do it yourself, then apply something like OptiCoat2.0 on the car. It will be done better, probably cost less or equal to what the stealership is trying to get from you, and perform better too.