Thoughts on how one PS3 can play split screen on multi TV with one race screen each....
Maybe there are special TV options to scale the TV picture by sections.
First there has to be a way split the image up to two TVs, both images are duplicates of each other, since it's just split and same signal goes out through an HDMI splitter.
Lets say we have a Tv on the Left called LEFT TV and one on the right called RIGHT TV.
If you have somekind of image software / TV function that can take the TOP half of LEFT TV's image and scale that into full screen then you can isolate just player one to LEFT TV. Use the same image software / TV function to capture the bottom half for RIGHT TV's image and scale that to full screen to isolate just player Two's view. This would allow two TVs to display a split screen multiplayer race on two TVs.
I don't know if this is how they did it, but it would be possible. Not sure what TV allows scaling abilities like I mentioned, but if it didn't then you would pass the video through a PC video capture card first, and these capture cards have the capability to scale images.
The resolution would take a hit from this scaling, but this would work.