the jbeam rn is very stiff indeed but im working on getting it to deform nicely in crashes and while being crushed between 2 T-Series trucks :3
Aside from the car being so light, fiberglass doesn't really dent, it usually just cracks, which BeamNG can't simulate very well.
As we can see on the pictures, interior is not the most interesting part of the vehicle I think (though it's high quality)
You somehow managed to make a car with a huge glass dome, 3 wheels, and less than 5 HP seem "Sporty".