 They actually used this Guayuli stuff, the rubber, for the first time in Indianapolis 500 racing. It was IndyCar racing earlier this year. They hope to commercialize this stuff in the next six years or so in passenger cars. Other companies are also looking for ways to make tires more sustainable. Goodyear is working on reducing the amount of petroleum that goes into tires. Unfortunately, I've read where they do that, they just wear out a lot faster.