As a Christmas present the developers of a brand new mod for rFactor have released a clip on Youtube with a preview. The absolutely massive looks very interesting with cars that raced at Le Mans and in the FIA GT, ALMS and Le Mans Series in the last two years. There are still cars missing, but they are supposed be added before the mod will be officially released. Currently actual professional drivers are testing the mod to make sure it is absolutely realistic. I can want to give this a try in the near future.

Link:
YouTube - LMS promotion video