Yep, the owners manual is your best bet. There are people pulling vehicles not certified by the manufacturer as being flat towable, but they are able to do it, and probably will never have any problems. But if something goes wrong they probably won't get any help from manufacturer either. If you want peace of mind, having the owner manual's approval helps alot. Remco, FMCA, or Motorhome Magazine Dinghy Towing Guide are all good places to start your search for a toad. Their lists will give you an idea of which manufacturers to look for, for the type of vehicle you'd like to tow. For instance, the dinghy guide will show which manufacturers allow towing automatic transmissions (and which models), and which manufacturers allow manual transmissions only for flat towing. Good luck and have fun looking for the right vehicle!
Steve & Nancy
2005 Itasca Sunrise 33', W20 Chassis, Ultrapower, Henderson Trac Bar
2012 Chevy Captiva Sport AWD, ReadyBrute Elite Tow Bar, Blue Ox Base Plate, Protect-A-Tow