If I were the property owner, closed or not, I would not allow any type of racing at all, due to liability concerns.
Of course....You could just swarm the place and get out before they realized.
Like the OLD SCHOOL rave culture where parties were always illegal, and there were 4 or 5 backup spots everyone would re-assemble at.
I promise you, they won't let you race there, if they know about it.
Not trying to rain on your race, but property owners are funny about liability.