Actually, kahit ano gawin mo.. there's no way in not having faded paint over time as long as you have UV rays hitting your paint. Paint protection helps lessens the damage a lot.. but it'll still fade over time.
Some paint will fade faster than others.
Personally, I wouldn't worry over it. I sometimes leave my car outside and not park it in even overnight and it won't really trigger my OC impulse to "save my paint" really.
Once you have paint fade.. see if paint correction works.
Paint fading is different from clear coat failure by the way.