i picked mine up from the rail yard. they had a guy drive me there, who had a release with him, thats what you need is the release. we both went in, he gave it to the people at the desk, he signed, they got the car, we looked it over, and i hopped in and went to the gate with the release the office then gave me, then i drove it back to the dealer, after i got gas! said 0 miles to empty on it and only had 13 miles on it. it was a great experience.
Not sure if the dealer has any say in this. I tried this a few years ago and the only people allowed in the rail yard were transports. There are 24/7 security people at the front gate and they check the trucking company manifest for clearance into the yard. Not sure if this is how all rail yards work but I know they all have guidelines. It is my understanding that the dealer "has" to sign for the vehicles and there is no way around that. Things may have changed though.