when you have less drag, you can use less engine power, when you need less engine power, power train sizs, mass, & the stiffness of chassic will need less, when they need less, the mass will also decrease, the brake, tire, and suspension can also make smaller, also the radiating neesed will less as less engine power, if you needed lesser radiating, the drag will be decrease again!
we have roll cage
the "release" what I mean is totaly break away from the car
if the pressure are on the canopy directly, that means it will on drivers' head if there are no canopy. easy to take a dead body out, and hard to leave the car life, which is better?