Gilbert Klecan of San Diego, won the national soap box derby in 1946, and looked like he just went 200 laps at Indy, but that’s graphite, not race grime.

He became known as the “Graphite Kid,” because he covered his car (and face) with graphite in an effort to reduce wind resistance.

Maybe it worked, because he ended up taking the win in 1946.

https://www.hemmings.com/magazine/hcc/2018/02/Soap-Box-Derby/3751474.html