I wonder if you can use the weight at the back of the car to make an aerofoil shape and reduce downward force -> tyre friction.

I sent this to my brother, who is a complete nut in his approach to pinewood derby cars. Artistic and over-engineered. He has a GRAND time.

His response to me:
I enjoyed his presentation.



I went one more step. Our track at church is not perfectly machined aluminum but is instead bumpy wood. My cars had a suspension system cut into the very thin wood. They would not bounce. People suggested a fund raiser for a new track. I said, "No Way, I like that track."