How do modern cars regulate temperature so well?

Lord Sparky said
That’s like asking why my 2003 Honda CRV looked like new 15 years later and my 1969 Dodge Dart self-destructed into a pile of rust in 1983 after 6 years of constant mechanical issues. Cars are made better today.

Cars are made better today....
Why can't my Cuda be made better....that is the essence of my thread.

Jeff