Fibreglass bumpers have a lot of benefits. They offer great finishing and are lightweight. Even if they are exposed to extreme weather, they won’t show ageing. They are less prone to damage from corrosive chemicals like brake oil and other kinds of liquids that go into the car. But all that being said, they have one big disadvantage. They fail big time in the matter of absorbing impacts. That doesn’t mean it will break with the slightest of bumps. But if you get in fender benders a lot, you should opt for something like ABS plastic or polyurethane ones. And finally, fibreglass bumpers are expensive.