It has two loading points in the station.
The loading point at the back get an extra "section" at the beginning of the ride just around the first bend (it's nothing special), but the first loading point doesn't get this.
So, the cars people talk about are actually just the 2 different loading points.
Yeah, it' kinda like Oblivion. Two cars get loaded and dispatched at the same time.
The first car goes off and round the track. The second car just goes around the corner and stops. Jigsaw then comes out on his bike and gives a speech while the first car gets to the lift hill.
The first car is the better ride as the pace is much better and you don't keep stopping. You still see Jigsaw in the first car, but all he does is laugh instead of give a talk.
So not a major difference, but something worth knowing.