Dealer wouldn't fix under warranty
Are you serious? Brother I don't think your yelling loud enough. This is BS for them to not fix a cracked POS plastic part under warranty.
I would highly recommend you contact Chrysler and have a chat with them.
I had a slight coolant smell, was out of fluid in the reservoir except for a dark sludge crud in the bottom.
I took it in to the dealer for a check up and a flush out, at first they wanted me to pay for everything. Even with only 7100 miles on the vehicle, and an extended dealer warranty.
After a call to the nice lady at Chrysler I was given a case number. The repairs were free and the tech even found out I had a cracked radiator. (Sorry I was not told or shown where the crack was)
They flushed my system out good and filled her up with new OAT. It was low after a few days so I bought a gallon of OAT and a gallon of dist. water. IT took about 1/4 gallon to get the reservoir up to the bump out thing on the side.
So far so good.