cracked fiberglass

alright well my sis has some z3 fenders, i have to fix them then i get them, how sweet

alright well one if cracked from the bottom into the fender about 6 inches, and the other is almost cracked inhave, i can fix them i just what to know how you would approach it

i was thinking about fiberglass hairing the back like a mofo (so futher cracks wont occur), and then bondoing the front to make it all smooth

what do you guys think