It's funny there is not much mention of towing in the handbook, no mention of not using fifth gear (auto) for towing. There is some mention of using a lower gear if the coolant temp rises when going up a hill and that's about it., No tow pack option except for a towbar, no mention of an extra cooling device. Sounds like MrBitchy think that towing is no big deal. My idea would be to keep engine revs in the peak torque band whatever the terrain.
Plenty of people using Challengers for towing, from what I've read the vehicle is basically very suitable for the job, keeping in mind that there are bigger more powerful tow cars around. It's a bloody truck, it has to be able to tow
On towbars, the bloody ripoff prices around. Ended up with a Hayman Reece 3 tonne rated for ~$465, bitch of a thing to fit but a nice peice of work.