fiberglass crack in extreme cold weather?

[jay42w8]

so I looked at the trunk lid on my ford exploder today...and there was a entire "line" down the middle gone...and to the right...u can see two more hair line cracks...its a fibreglass (im guessing) cover ....could this have been from the cold weather last week???...theres no sign that it was hit by anything

anyone know if this is coverd by basic insurance?

[schurchill39]

Could it body filler, because it will crack in cold cold weather if its layered on thick