What's the difference between a dealership coating and a professional coating?

The product matters far less than the preparation, and that is where the two differ. A coating sold as a dealership add-on is usually applied quickly, often as part of lot prep, to paint that has not been decontaminated or corrected. There is rarely time for a clay bar, an iron decontamination or any paint correction, and the car often goes straight back out into the sun. Applied that way a coating bonds poorly and seals in whatever swirls were already in the paint. Our process takes the car for a day or more. Full wash and dry, clay bar treatment, iron and fallout decontamination, panel prep, paint correction if it needs it, then the coating goes on in a controlled environment with proper time to cure before the car leaves. Because the surface is genuinely clean and level, the coating bonds the way it is designed to. You can see the difference in the water: it beads harder and tighter, and it keeps doing it for a lot longer. The other difference is what happens afterwards. Ours carries a 3-year warranty as standard with a 5-year option, and there is an annual maintenance visit at $120 where we wash the car, check the beading panel by panel and reapply wherever it has dropped off. Worth asking what the dealership's coating is warrantied for and who maintains it.