[toast0]

> it doesn't explain the use of chrome, rectangular or round headlights instead of molded headlights that integrate into the bodywork,

Interchangable standardized parts are a bad thing now?

[porphyra]

If you compare, say, the Peterbilt 579 and 589, you'll find that the former is way more modern looking and aerodynamic and the latter is very classic and old school looking. The 579 is also vastly more fuel efficient. I'm fairly certain that the classic design of the 589 is entirely for aesthetic reasons rather than for part interchangeability.

https://www.peterbilt.com/trucks/on-highway