ther is a start line on autoX to let us set a circut in AutoX to have a race, but it just got one way, so we can't any anti-clockwise circut.
so, I hope that we can have a AutoX reverse track.

Not possible for more than one car to start in any other position or direction other than the start/finish position. Suggest placing an immediate U-turn corner after the start/finish line/lights, thus forcing a reverse direction.

So ok not quite what you wanted, but its a work around.

Quote from scania :

ther is a start line on autoX to let us set a circut in AutoX to have a race, but it just got one way, so we can't any anti-clockwise circut.
so, I hope that we can have a AutoX reverse track.

Rotate the start and finish lines 180 degrees maybe?

No, becuase then it's only 1 car starting, not a full grid like if you don't place a start.

That's why I said maybe. I've never made an autocross layout so I wouldn't know, just sounded like a logical answer.

Quote from mkinnov8 :

Not possible for more than one car to start in any other position or direction other than the start/finish position. Suggest placing an immediate U-turn corner after the start/finish line/lights, thus forcing a reverse direction.

So ok not quite what you wanted, but its a work around.

it may have no enough space to u turn sometime.