Whenever I put the top down I can see the elastic bands beggining to fray pretty badly. Does anyone know what this elastic is for? Is it just to help put the top up and down or is to keep the roof buttress tight when the top is up?It doesnt look like a part that can be replaced as it is sewn into the roof. Once these suckers break ( and it wont be long now ) whats gonna happen to my top??