I just called Dining earlier today about my Sci Fi ADR and the CM told me that as far as requesting a car table, you would need to do that at the podium when you get there for your ADR. He said that most tables in the back were handicap ones for wheelchairs. I know different CMs say different things though, so you may want to check anyway.
When you make your ADR's they will make sure that they have enough cars for that time period. When you get to the podium, you can request the TYPE of car - everybody faces the front versus everyone faces each other. I was just there last week and that is what happened, it was also that way last August when we ate there.