I nice idea IMO. The speed gained at point 5 would be absurdly high, I guess.
The tracks in general could use some insanely brutal changes in terrain height/elevation in general.
I think there is a similar track section on Transport reverse, except that at point 3 on your drawing the cars are launched forward and back on track, not down into the abyss.
BTW, having absolutely no skill in drawing things, I love the way how you drew the cars.