Huh? Cash For Clunkers ENDED nearly sixteen years ago. Trying to paint that as a reason why auto insurance is higher now is a poor justification. Cash for Clunkers resulted in not just removing fuel inefficient cars from the road, but they ended being replaced with newer, generally safer vehicles.
secondly the auto in question is a simple 4-cylinder design, manual shift and no electronics in the two doors. A definition of safety that includes feedback msgs while driving, or constant location tracking.. is something about which reasonable people may disagree.
[0]: https://www.bar.ca.gov/consumer/consumer-assistance-program/...
The 10-15 year range (a large group getting new vehicle credits) is likely relevant in second hand ownership and used car markets, so it is likely highly relevant.
"Generally safer" is a detail to dig deeper into, do the cars have more safety features and are they better performing, no doubt. Has the US seen fewer pedestrian deaths, fewer collisions, no. Cost to repair also went up significantly.
Possibly worth mentioning is the financing model changes of car manufacturers over the last 3 decades.