I have an 08 with the Trailer Tow Group. It comes with:
- Class IV receiver hitch;
- 7- and 4-pin wiring harness;
- Heavy Duty Service Group (auxiliary transmission oil cooler and power steering cooler);
- Skid Plate Group - tow hooks and skid plates for the fuel tank and transfer case;
- 3.92:1 axle ratio when you have both the Trailer Tow Group and the Hemi engine; and
- Transfer case with low range on 4x4 models.
I think the Heavy Duty Service Group could be ordered without the Trailer Tow Group, but I wouldn't expect that to be very popular - people generally wouldn't want the beefed up cooling unless they're towing,
AFAIK. Ask the dealer for a build sheet so they can demonstrate that the auxiliary transmission oil cooler and power steering cooler was factory installed.