Thanks everybody.
@Michael:front overhang (from the front axle)is 890mm and the rear overhang (again measured from the axle) is 810mm...I am confident the chassis structure provided by gr500 wont brake in the middle.Bending the back helps the aerodynamics and (i think) the aesthetics too.

Lowering of the back reduces air drag but increases lift. That is not good for a high performance vehicle.

Great work et thanks for STL