24 hours would be very boring. After all, in real life nobody drives 24 hour races. They drive in groups of 3, 8 hours or so each.
I would like to see Le Mans 3 hours, if Le Mans is in. Estoril 70 laps if Estoril is in.
There's no real need to restrict races to group C/GT1/LMP types only. After all, presuming F1 cars aren't in, they will be easily the fastest cars in the game. Then again, if GT4's AI is anything like GT3, you could probably win Le Mans in a Viper RT/10.
I would like to see Le Mans 3 hours, if Le Mans is in. Estoril 70 laps if Estoril is in.
There's no real need to restrict races to group C/GT1/LMP types only. After all, presuming F1 cars aren't in, they will be easily the fastest cars in the game. Then again, if GT4's AI is anything like GT3, you could probably win Le Mans in a Viper RT/10.