Ford has made an offer to do what? install the pump? buy back the car?
The bigger question becomes 'how many more times can this happen before Ford refuses to replace the transmission under warranty?'
If Ford is offering a free transmission cooler without conditions (as in 'no more free transmissions') then take it. It will only increase the trade-in/resale value of the car. My Ford pickup had a factory installed transmission cooler.
Having had it fail twice already, I would be more inclined not to risk it and replace the car if at all possible. I would get the car back, remove the tow bar base plates, tail light kit, etc and return the car to stock condition - then private sell it (eg: craigslist).
If you attempt to trade it in you may get questioned by the dealer as to why the car's service history says that it is on its 3rd transmission. 'Burned out after flat towing' is an answer they may run away from. A private buyer is less likely to make the sale conditional on a carfax report. If they were smart, they would.
2005 Cruise America 28R (Four Winds 28R) on a 2004 Ford E450 SD 6.8L V10 4R100
2009 smart fortwo Passion with Roadmaster "Falcon 2" towbar & tail light kit -
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