I agree with you Tom, this shows up just as much on the electronic side of thing as well, take for instance a PCB in an ECM or an Instrument display, the quality and amount of solder applied to the board will determine how it will stand up to vibration and the environmental change of its location, so a cheap solder applied in a small amount can be seen time and time again with the dry joints we all find in this line of work,
It is not practical for the manufacturers to spend another £1 per ECM, on good quality solder at the correct amount to secure the components to the PCB, then have it last for twenty years or more when they can introduce a failure life time of four to six years, this also shows up with the grading of the components used in the motor trade, whether it be an IC or a wheel bearing.