They do focus on technology, but the rules are strict, and hardly ever change a lot. The basic ideas behind the Cup series has not changed much in a long time.

They do focus on technology, but the rules are strict, and hardly ever change a lot. The basic ideas behind the Cup series has not changed much in a long time. But the implementations are quite amazing. Just look at the engines themselves. Or the safety improvements they have developed over the years. Plus, NASCAR is about being good at cheating and being great at not being caught.