Mine didn't have the tow package (05 V8 RWD). I added the class III hidden hitch, trailer wiring, and accesories (chrome ball and bar with locking pin) myself for less than $250.
I went to the dealer to see if they'd install an auxillairy transmission cooler, and they said it would void the warrantee. I plan on installing one, but not until the warrantee expires. I only use my hitch for a small utility trailer, which is less than 2000 lbs with my harley deuce on it, so I think it will be Okay for now.
I do have a couple of additional trailer hitch questions...
Q: How much power loss do you think there is between the belt run fan used with the Towing package and the electric fan(s) on the non-towing version?
Q: How do you turn off the backup warning when trailering? Whenever I backup the trailer the thing beeps the whole time, as it senses the trailer and hitch. I'd like to be able to turn it off.