I also completed it with the 2001 Tokyo concept. It seems to be fairly light compared with the newer GT-Rs as it's down around 1200kg when all three weight reductions are applied along with the window weight reduction. After playing around with the modifications to get it to the maximum power rating and a few tweaks with the suspension (don't have to bother with the FC transmission as the stock gearbox is fine) I took it to an easy win by around 10 seconds. The car handles really nicely - better than the production GT-R in my humble opinion.