Here's an example, before WWII brake lines were made out of Monel, a corrosion proof material aside from galvanic. Nickel and copper being expensive and needed elsewhere the lines were made then made from painted steel. After the war steel lines became the standard.

The cost difference is small but it's indicative of a larger issue of disposability. One of the reasons Japanese vehicles started to dominate was that they lasted longer. This is due to better tolerances, more efficient engines, and more robust component design.

The Toyota production method, lean and just-in-time were mostly methods for rationalizing better systems to eliminate waste within production and to minimize inventory. Such methods don't inherently make a better car though they leave more io the table to spend on coatings, quality parts etc.