Hmm maybe something to consider for the future Maker Pinewood Hill (wood track) Derby: Where the cars must go UPHILL using only certain classes of power: Wind-up springs, rubber bands or the small CO2 cylinders.
Same track could be used for regular Pinewood Derby but with a change: Gravity Defying Cars! Be a good publicity I suppose. Throw a challenge out to other Makerspaces and Universities (let the Engineers see if they can outdo creative makers.).