Increased regulation let the push to more fuel efficient vehicles.
I kind of like out RAV4 that has more power than my '54 Chevy coupe and gets 30+ mpg.
If it hadn't been for regulation, and competition from overseas (The American car buyer will never buy small cars, they want Cadillacs and Buicks) and we'd all still be driving cars with 9-18MPG inefficient motors that needed valve adjustment 2x a year and a head job every 50K miles
No, it wasn't CAFE standards that did that.
It was $5/gallon of gas after Katrina that did that.
Competition from overseas, yeah I'll give you that.