"They did this mostly by using better paints and making sure cars and car parts are painted more thoroughly."

Their cars last longer because they put more emphasis on durability and longevity than bleeding edge performance, for parts that matter in extending overall operating life of a vehicle.

Germans may use their dollars differently, designs that require tighter tolerance for higher performance. They may also skimp out on actual durability testing, serviceability of parts, etc. Again, prioritizing performance over other attributes.