Since the advent of polyurethane we've found them unnecessary.
If about the other type as a kid growing up I wanted a soap box derby car, that never happened. Yet with youthful determination of scrounging and an couple visits to a repair shop I sourced 2x4's a piece of plywood, a bolt some nails and 4 matching transmission bearings.
Whittling down the 2x4's to accept the i.d. of the bearing and fixing them with nails through the nubs of the whittled axle. The rear axle was nailed to the ply, the front with the bolt and finally a piece of rope nailed to each end of the front axle became the steering. We had great fun with those on the steep hill we lived. Especially spectacular was our twilight runs when we'd borrow dads can of ronson lighter fuel and spray it on a back wheel as we sprayed sparks, then flames.
Might be cool to build a wall hangar for old time sake.