Donohue invented the original downforce generating device....I was a FAN of the Can Am cars .https://www.amazon.com/Unfair-Advantage-Mark-Donohue/dp/0837600693/ref=sr_1_1?crid=1PUWOWZP4S4GZ&keywords=the+unfair+advantage+mark+donohue&qid=1673905033&sprefix=donohue+unfair+a,aps,825&sr=8-1
It's a "must read" for anyone who races. Most of the content comes from his time in Trans Am and Can Am. Donohue was a mechanical engineer and came up with some clever ways to interpret the rules "creatively" and gain an advantage.