The Japs are very smart and well talented to modify cars.
Very subtle as well which is different from the Yankee who are very loud and more extreme.
Say for example the GTR may have doubled the HP but doesn't look much different from the ordinary road car.
On the other hand, the Yankee may have drawn a thunder bird on the bonnet or fire on the side and add a spoiler that can land a plane.
Good Job Japs.