The topic of flat towing versus dolly towing has been mentioned all over this and other forums, under any number of topic headings.
Suffice to say, flat towing has a BIG consideration that dolly towing has to face to a much LESSER degree.
It all comes down to automatic versus manual transmissions. A LOT of vehicles with an automatic tranny need the engine running to provide cooling/lubrication to the transmission part of the vehicle. A manual transmission does NOT have this concern in a lot of cases.
CHECK THE OWNERS MANUAL!!!!!!!!!! Can't say it enough.
Food for thought as far as SMALL SUV AUTOMATIC vehicles.........
Ford Escapes pretty much stopped being able to flat tow starting in 2013 because of a major redesign
Honda CRV has stopped being able to falt tow as of 2015 because they have a new CVVT transmission...( a very popular toad of choice)
Chevy Equinox/GMC Terrain still flat towable
None of the import small SUV's flat towable
Larger SUV's vary from this point.
Just be aware, and noboby gets hurt