Awesome, great to hear it works! But you should definitely publish your tweak mods so non-modders can try it out too.
PS: For laps/fuel, you could start the race with a couple more laps than you need to get the AI to fuel a bit more, then change the lap count to the correct amount once the race has started. That should get them to the end. (The only problem I can think of with that is that the replay stops recording when you change the lap count in single-player)