Yesterday I discovered some minor damage to the rear door of my Mazda 3 (purchased three months ago). I don't know how or when it happened. It's quite a shallow dent but it looks like the paint has cracked.

I wouldn't normally be too worried (just very annoyed!) but it's the first time I've had a brand new car. Also, it was purchased using a PCP deal so has to be handed back in three years time in decent condition. Can I claim on my insurance or should I leave it?