I've bought the new 2015 Mazda 6 GS in the end of September last year.
And I decided do not do any additional rust protection: it is a new car and I assumed the proper rust protection should be done on a factory line in Japan.

In the end of July I have noticed rust leak trails under the trunk car plate. And when I took off plates I see the paint is bumped in two spots and yes - there is a rust !

Overall I was happy and satisfied with this car. But that - fully changed my opinion about it:
- The car is less than one year old! The car suffered one Toronto winter season while staying on the driveway overnight.
- The place were rust was found have not got any physical damage or impact - that for sure!
- I have not got any explanation from Mazda dealer (Maple Mazda - Toronto group dealers) - why that can happen! They just propose to paint it and refused to change trunk cover!
I know: the rust is like a contamination and small chance is that will fix it for years.

Does anybody have the same issues?

 

They would have to more than likely paint a new trunk cover and/or would be really hard to get (especially in same color + shipping + wait), so just get yours painted. I think they are fair.
As long as inside is good. Oil spraying inside would be good.