Rather than tell you what vehicles is best to tow, I'll tell you how we got our last toad. During one of our trips we heard that Enterprise rentals was selling some of their vehicles that were "hail" damaged. We picked up a Chevy HHR, with minor hail damage that can't be seen from 10 feet away. It had less than 10,000 miles, came with a full factory warranty, and cost us less than 1/3 of the MSRP. Obviously this vehicle was maintained and detailed after each rental and it was spotless when we purchased it. That was 50,000 miles ago, not counting the miles that we have towed it.
In any case, the point is that if you do not have to have a spotlessly clean brand new vehicle, you can save a lot of money and pick up a vehicle that will suit your purposes, by checking with the rental companies.