I bought an new antara diamond 2.2 165bhp in march, and towed a swift charisma the following day, the caravan weight being 1495 kg's NO problem, just do not labour the engine, know need for running in miles
I ALWAYS run in my cars and I always will do, I certainly won't listen to a car sales person who doesn't know one end of the car from the other. I always take it easy for 1000 miles. Find out what revs the car does in top gear at 70MPH and that is the ball park revs you don't go over in any gear. Also no labouring the engine either, that is even worse than revving. Do the same with my motorbikes too.
As for towing a caravan in a brand new car...I wouldn't even dream of it before a thousand miles. But each to their own, it's your money and your car.