Thoughts on next tow vehicle

Also want to say, I'm trying not to buy a new vehicle. I've always bought vehicles in the 3-4 year old range. My thought is that if I bought a brand new van and had the tow package installed, I could go out and buy a crew pickup. It would have a lot more miles and be older, but it would obviously be a more robust tow vehicle.

Anyone know how I could track down a used van with the tow package? It doesn't seem to be something dealers advertise on the listings.