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:dunno:

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