Will a ceramic coating affect the value of my car?
The difference in second hand value between a car in poor condition and one in excellent condition can be thousands of pounds. As a ceramic coating will help you keep your car in excellent condition, it will most certainly help it retain value over time.
It's also a plus-point to be able to say a car has a ceramic coating with a transferable warranty. This might not add much to the value of the car, as modifications generally don't, but it might make your vehicle more attractive than the next one on the list.