prime example why phones are better for stuff like this...
sorry I'm no help, but your post, regardless of country, shows me that buying a factory NAV is only good for a year or two after purchase and is not worth the added cost at time of purchase...unless, the car company shows continued support for previously sold models. They will update coil packs, and refine other consumables, but the NAV data is never touched again after the car/model leaves the showroom floor.
Is your NAV data on an SD card? If so, can a new SD card for a newer, current model year CX-5 be used to update your 2015? The sad part is, you will probably have to buy it, making it a less than desirable upgrade.