I think the race you're referring to from Copperbox had more to do with boost than anything else. The cars had no trouble making up gaps of a second or two but all of a sudden they are the exact same top speed when they are running down the straight at the end of the race.
I haven't seen the interior of the Bugatti. Does it look like a purpose built race car with a full roll cage or is it still the stock interior?
Yes, the Copperbox race is the one.
There were some small differences in top speed, with a few cars successfully making the pass.
I remember the 458 fighting the 4C though and thought the Ferrari struggled and even may have hit the rev limiter at one stage.
But it could well be boost too.
I guess the obvious thing was that no car destroyed any other on the straight.
Which is a little unusual considering the various different types of cars doing battle.
Why, I can only guess.
The Bugatti.
I think I've seen the interior, but wouldn't know where to start looking for it.
From memory though I think it's quite a lush, full interior.
I recall it showing a map of La Sarthe on one of the displays.
Perhaps I'm confusing it with another car, but I don't think it's a stripped out bare-bones interior as you are questioning.
There are some details of the car on the GT website though.
So I took the lead from there.
"The virtual race car was developed in close collaboration with the Bugatti engineers and is based on modern racing technology and aerodynamic analyses. To attain the performance goals, the Bugatti Vision Gran Turismo is driven by a W16 engine, which delivers the engine power of 1,230 kW (1,650 BHP) and 1,580 Nm (161.1 mkgf) to all four wheels. The engineers have calculated that the Bugatti Vision Gran Turismo can drive at over 400 km/h (250 mph) on four sections of the virtual Le Mans track reaching an overall max speed of 447.59 km/h (278 mph).
The Bugatti Vision Gran Turismo is the ultimate race car, and at the same time a true Bugatti."
http://www.gran-turismo.com/au/vgt/bugatti/
Make of that what you will I guess.