UPDATE: It turns out the "missing" cars only show up if the game is running in linked mode! Check out my latest post for details.
If you've played Le Mans 24 on Supermodel, you may notice that no matter how well you do, you never seem to be able to reach 1st place (or even close) in the 24 hour race. The reason for this is that not enough cars appear for the player to overtake. Oddly enough, the sprint races are unaffected and it is possible to finish 1st without too much trouble.
This was something I noticed back before Supermodel 0.2a came out and I e-mailed Bart about it. Neither of us had any idea what was causing it. I decided to wait for 0.2a to see if the problem would have been fixed. Sadly, it hasn't been.
However, I've noticed something since then. In the game, you see enemy cars pop up in both their original colours (which you can choose) and also alternate colours (which you can't choose). For example, the main colour of the Ferrari is red, and the alternate colour is blue and yellow. Look closely in the sprint races; each car has an alternate colour.
Skyline original: white/pink
Skyline alternate: white/blue
Ferrari original: red
Ferrari alternate: blue/yellow
McLaren original: blue/orange
McLaren alternate: green/yellow
Porsche original: white
Porsche alternate: black
Sauber original: silver
Sauber alternate: black
Mazda original: green/orange
Mazda alternate: white
What I've noticed is that running the 24 hour race on Supermodel, the alternate colours of cars never appear. In the actual arcade game, the alternate coloured cars appear just as frequently as the main coloured ones, this means more cars to overtake. Some cars are to be lapped, these are only ever alternate coloured cars (which never show up in Supermodel, hence you never lap any cars). Funnily enough, in the 24 hour race, no McLarens ever appear. This is not a Supermodel bug since they don't appear in the actual game either.
In a nutshell, for every 5 cars you pass using Supermodel, you should actually have passed 7 and lapped 3 (it seems that 3 of the 5 alternate cars are to be lapped).
Here's the video that I used as a reference: http://www.youtube.com/watch?v=LgjK7D9_Uq0
The big question is, why aren't the alternate colour cars appearing? I'm probably going to build the debug version of Supermodel to see if I can find any clues...
EDIT: Built the debug version, tried to debug - crashes every time. Strange since the build runs fine with the debugger disabled.