I got sidetracked a little trying to make the car work..
now the engine still has no physics engine whatsoever
(I tried out bullet was so disapointed I don't even plan on adding one anymore)
long story short I had this idea of making the car the old way
from simple distance springs
there is no verlet, it's simple euler stuff
running at 750 fps 
it's made out of 6 spheres and about 18 springs
literally a car held together by glue and prayer
adding a mesh kind of hides the jank - but not by much
the prototype was really promising
ingame there were troubles 😓
turns out getting the basics to work is just start of the journey
one thing I was worried about is how to flip the car back
(you don't have a gravity gun after all)
but then just kicking it and it magically flips
not only worked but it was the easiest part
overall I'm not sure what to do about it now
it's good enough to keep it in the game
but not good enough to build serious gameplay on it 🤔
and of course I still only have the test interior 😓