The only time we moved long distance and had to deal with cars it was from DC Metro to South Florida. To move our two cars at the time we took the
AutoTrain which was great. Since we were moving in May it was opposite the "snow birds" so we got a heck of a deal on it. With a sleeper cabin it was less than the cost of the gas for the same trip.
The only downside was when we arrived and they unloaded the cars.
One of our cars was the first one off (top deck in the back) so we thought we were golden. After an almost two hour wait while other cars were unloaded it turned out our other car was the last one off.
Basically, when they load cars they load them top row, front to back, then bottom row front to back.
When they are unloaded they are top row back to front, then bottom row, back to front.
Our cars had been loaded following each other, except we ended up being the last car loaded on the top, then first car on the bottom, which made us first and last off.