I know much has been posted about the front fender cracking on the 1800's due to adding an extended fender, however I've always been a bit of skeptic about that. That's just an opinion, since I have only 3 post on this board I might not be allowed to have an opinion yet! Ha! gray red rider I do hope it works for you though, Good Luck!
I had an '09 that didn't have a fender extension on it and the fender was fine. My trike is a '13 that I purchased new as a trike and came with an extension on it. I replaced my broken fender before I replaced my second front tire at 28K. I don't remember the exact mileage when I replaced it but I'm guessing around 15K or so. Also have a friend that his fender broke also. Both trikes had the same extension on them. BTW my '09 only had 115K on it with no cracked fender. I also pretty much rode both bikes under the same conditions. One thing I have given thought to is the rake kits on trikes change the airflow with the fender extension but that's just a thought nothing to back it up either way.