I tried and tested the Twingo on that track doing hundreds of laps and this was the best blend of power and handling/gearing etc so it would still be fun. Its an a class car but at the bottom of the numbers if you get what I mean. If I had made it full on A class it just had too much power and was pants to drive.
This is why with my 106 I want to stay NA and have a really good handling car that can take more power but won't have it. There's more fun in having something you have to annihilate to go anywhere quickly. Turbo its all point and squirt which is fun in a way but not my thing personally.
Forza is interesting as its very accurate in parts and absolutely terrible in others.