I have towed a lot, and see some rookie information on here re towing. Thats ok, its your responsibility. I frequent a racer forum & some racers trailer with their car in neutral. The thought is, wearing shiny spots in the cylinders and causing increased wear. Not transmission failure. Of all the stories I have not read of a damaged transmission or motor. Just concerns. People with way more experience than me. There is also lash in a drive train, between the trans & diff.
*Redundancy in safety is a good thing*. Whether its straps, chains, along with chocks, emergency brake set, and put in gear. Cross your chains or straps. Some (a good idea) lash their car down in neutral then when secure put it in gear for less tranny loading. Double check, triple check retighten as straps and chains do loosen. Better safe than sorry! Human error is probably where vehicle movement comes from.
I do wheel nets on airline track, e brake and set in first gear. I'll let you know if I blow a trans or get blow by this way. Being an ex CDL/professional driver, I know, its always the drivers responsibility. Even if a chain or strap breaks, you will be the one ticketed.
Another train of thought is to use wheel net or tie off on suspension components so your car 'floats' and doesn't feel every bump as much.
So I respectfully agree to disagree. Sorry for the long winded opinion.
EDIT: A copy & paste I found...
No matter which method of tie down , you should always transport the vehicle in gear with the emergency brake engaged. Friction is your friend and momentum is your enemy. Whatever a transporter can do to stop the vehicle from gaining any momentum in the event of a hard stop or a crash the better. Both chain and strap systems are effective in keeping the vehicle on the trailer - when used properly. Either system can be rendered ineffective in a hurry if the vehicle gets a chance to start moving before the strap or chain gets a chance to work. When choosing whether to use a strap or a chain, you should always take into consideration the profile of the vehicle (is it high or low), if the vehicle is equipped to properly handle chain frame hooks, if the wheels are smooth enough to use a loop strap without damage, if can you access a control arm or a straight axle for tie down, and many other factors. Common sense will normally prevail.
No automobile manufacturer has ever specified any of their vehicles be transported in neutral. The only exception in the thousands of models ever produced was the 1993 and 1994 Pontiac Vibe and the 93 - 94 Toyota Matrix. These vehicles shared a transmission that was designed and built by Toyota. For some reason, Toyota engineers insisted the vehicles be transported in neutral. Unless you are hauling new cars for an automaker, keep the car in gear.