Fiberglass Rear Fenders?
 

such as the burn out/feed/ petit..

what are the chances of cracking?

if someone were to lean against it would it crack?
or what if a door hits it in a parking garage?

i would think it would crack but i have no experrience w them nor do i know anyone with them
please post ur experiences, because i love the look but my car is a daily driven fd

No, they won't crack from someone leaning against them. A door would not crack them unless the person that opened the door just realized he was being cheated on. They are prety sturdy. I had mine molded, and they were firm.

my car is molded and i have fiberglass everything.
last time i changed the motor out when leaning on the fenders they do crack.
not sure yet if its just the paint or if it goes deeper because i havent repainted it yet.

i also have hood pins and all around the pins are cracks from pushing down on the hood to close it.

i am pretty sure its just the paint thou.