WPL leaf spring. With realistic mouvement and improved height.

Only need m2*10 bolts with no nuts.
No need to drill the holes and direct screw in the plastic mount.

You may need this https://www.thingiverse.com/thing:3356350 for the front to avoid problems with the factory steering arm.

Tested by my son and I, works well even with the straight forward driving of my son.