Poor Paint Thickness and Rust on CX-5

I have an 20 month old CX5 in Black Metallic and I wash it regularly and provide a good wax every 3months. Before it's scheduled service I noticed a small mark on the front of the roof about 6 inches back from the windscreen. It appeared to be a small stonechip with what looks like spiders legs under the paintwork. I have had it inspected by an approved bodyshop and they say it is due to a stonechip and therefore will not be covered under the anti perforation warranty. The stone chips I have on the bonnet have no corrosion evident but only the one on the roof. The bodyshop did a paint thickness check and were concerned that the thickness on the roof area is only 70 microns thick and the bonnet area is 90 microns. They informed me that all New Mazdas have this potential problem and the thickness they recommend to provide adequate protection is at least 100-120 microns (some difference). I will be approaching Mazda with a request to support the repainting of my roof under the warranty so watch this space. A point of note is that seagulls do use the roof of cars as a good place to discharge with their very acidic droppings. Hopefully I will get it sorted before it gets any worse.

Have had this same problem on mine with three perforations. I have also had mine through a 10 minute hail storm with half inch hail and no damage occurring. I share your frustration but I don't share your blame. I had my roof repainted under a comp insurance claim for the price of my deductible after the factory rep rejected my claim. Was his suggestion to go through the insurance. Good luck with Mazda, doubt they'll cover it. There's not much that will stop flying stones from breaking through bare paint.