you can look at the way i do my cars, with an invisible block underneath and, with the geometry actions, select the car and put bearings on each peice you cut. the invisible block should be behind the car, so the peices dont lock to the background.
also, i need to mention, put the bearings on brake (tip: dont add a bearing to the invisible block behind the cut-up car).
you dont have to fix the suspension, the car is a crashable bugatti chiron
for the whole time i didnt look at anything but the crumple of the body, and i also saw nothing wrong with the suspension either
honestly, if it's crashable, and it's bugatti, i think that's good enough
dont stress