The closest I've come is a towing with a 6 cylinder Jeep Cherokee (2100 miles in 2 1/2 days without problem) . It did fine with 3.07 gears, 5 speed and around 2000 lb total. I wouldn't want to pull a tandem open car trailer with it though.

The Dakota is a stouter vehicle but the limiting factor would be power and gearing. I'm a litle surprised with the 7000 lb tow rating and the V6. If it has steep gears (3.91, 4.10) and an auxiliary transmission cooler it would probably do OK if you are not in a hurry. Without the steep gears and cooler, it would be dangerously slow and hurt itself trying. If it matters, I doubt U haul would rent one of their car haulers with that stated combo.