I had two grandsons go through this over here in the land of jailed ex-governors. Eventually both wound up with QMs -- Grandpa wound up "helping out" (purchased a new Bullrider one season, engines & tires other years) but what are Grandpas good for otherwise
It eventually led to one Dirt Grands championship (Senior Honda) and then a 600 Mini before it all ended when the world of girls and "my own car" entered the boys' lives.
Lots of fun, new friends, family togetherness, etc. to be had with QMs.

Take your kids to try it, but be warned: it can be the start of a budget-stretching form of family recreation