[David McLaughlin]

Weight location is very important. It needs to far enough back to allow gravity to do it's job at the lower part of the ramp but forward enough to keep the front wheel on the track. polished axles and wheels are next. If the car is smooth and the weight is in the right spot at the highest possible amount, it doesn't mater what the car looks like.

I try to have my boys do as much as is safely possible. My oldest will use the scroll saw on his own but the youngest will only do the larger cuts to keep his fingers away from the saw. Both will polish the axles and wheels while I keep my finger on the drills trigger. Both paint their cars un assisted though my OCD may make me to a couple small touch ups. I'll usually clear the cars as the fumes are pretty strong with clear coat even with a mask. Basically I try to put my hands in to help build the best they car do with guidance.