If leather is optional, then they are already building interiors without leather
Changing the amount of something has big effects on supply chain, logistics, and costs. Mass production is all about volume and lead time.
I don't believe the suppliers need a nine year heads up.
I didn't say that. If you buy less of something, it'll cost more per unit. Manufacturing line utilization and re-tooling are also important. Someone has to figure out how to change everything cost-effectively.
I find it hard to believe they need 9 years to that