Hornbein said:

The most important thing is that the mass be toward the rear of the car.

Yeah, you need a massive battery in the back, for the electromagnet in the front:

https://www.nytimes.com/1973/08/25/archives/boulder-colo-shocked-as-boy-hero-is-stripped-of-title-in-soapbox.html said:

An electromagnet imbbeded in the racer's nose and powered by a battery concealed in its tail was activated by a button hidden in the head rest. The Gronen boy switched on the magnet by leaning his head back between special guides.

When the rectangular steel starting gate fell forward, beginning the race, it pulled the magnet and car forward quicker than gravity pulled the other racers’ cars forward.

My pinewood derby also occurred in the 60's - I lived as close to Kennedy Space Center as is physically possible (my father worked on Apollo - just like everybody else). Dad left me to my own devices (thanks, in retrospect), but I remember bootleg lubricants, outlaw axle polishing, illegal ballasting, hidden bushings, and all kinds of chicanery (by over-involved nerd fathers). It was common knowledge that more potential energy at the start resulted in more kinetic energy at the end. I didn't win.

That's the technological innovation, that the Appolo program inspired!

My brother "helped" me by telling me that that the weight of the car didn't matter because all bodies fall the same regardless of their weight.

I lost miserably.

Herman Trivilino said:

My brother "helped" me by telling me that that the weight of the car didn't matter because all bodies fall the same regardless of their weight.

Pinewood derby in a frictionless world would indeed be very boring.

A.T. said:

Pinewood derby in a frictionless world would indeed be very boring.

Not really. Weight and its distribution would still matter and there still could be air resistance.

Pinewood derby in zero gravity and no friction in a vacuum, that would be loser.

Hornbein said:

Not really. Weight and its distribution would still matter

For steering and directional stability?

Hornbein said:

... and there still could be air resistance.

I included that under friction.