I do tow a vehicle which the manafacturer says can not be towed "4 down" as we say. (Flat tow) and I see TOM has already told you how, Remco, they are the towing experts, I would make their website my first stop and one of their dealers my last stop. There is no better way to go than REMCO.
That said, for many vehicles REMCO offers a choice, one is a lub pump, this pumps transmission fluid using the power of the Tow Vehicle battery and thus keeps the bearings and such in the transmission well lubricated. The problem is sometimes these pumps fail and, Well, Remco guarantees the $500 us (about) pump, not the $3,000 (us) transmission (Again about).
The other option is an axel lock or drive shaft disconnect, The axel lock is based on the same technology as the Wagner Manual Locking Hub used on JEEPS for as long as I can remember (I remember seeing one in the early 60's) and is very reliable.
The drive shaft disconnect is a spline clutch which is also technology which is many decades old, both are very very reliable, I've not ever heard of a failure With these devices you tow the vehicle in PARK. Cost is simular to a lub pump (Often the difference would not buy lunch) though instalation may be a bit more (I can not compare)
With these devices you tow the ride in PARK and don't have to play games to not run up the millage. When you hook up you turn the car into a trailer, no power to the wheels. Should Mr. Theif try to unhook and drive off he can go 200KPH per the speedometer but he won't be moving till the nice policeman puts him in the back of a vehicle which takes him where he don't want to go.
(Unless of course he cuts and runs on foot) since there is no power to the wheels.
Another unadvertised advantage of the disconnect/lock method over the lub pump is this. I know when I disconnect, if I have the tranny in nuteral the speedometer can easily hit 20Kph or more just from the friction of the transmission fluid over the gears. I assume this translates to "Drag" if I were towing in nuteral with a lub pump (Not to mention the power to the pump) with the axel lock this all goes away there is very clearly no drag