You will find that all Mobiles have a noise that is all their own, kind of makes them have a personality. Some have roof rumbles, some have sidings that pop when they expand from the sun heating them up. They are noises that after a while you won't even hear.
They used to use "rumble screws" to reduce the noise, but since you were putting holes in the roof it soon became a situation where you were trading one problem for a bigger one. If you can live with it I would do just that.
"If I can't fix it, I can screw it up so bad no one else can either."