I should point out that I have nil direct experience in these matters, as my own Y is probably still in 1000 pieces awaiting assembly this or next week. I only suggest what I mentioned above because that's what I'd do, and also because I'm just an old stubborn dude.
EDIT: Oh, and I wouldn't use the word "cracked." Perhaps "de-laminating," or "peeling." They must read the words cracked or broken too many times in the course of denying claims all day long. Also, that part is more refered to as a side repeater, and not a turn signal.