Cars are built (for the most part) by robots, the parts are smaller and more durable, and most models on the assembly line are a mirror of the one preceding and the next one after. It is a totally different assembly procedure. It would be nice if RV's approached closely to that level but it really can't happen.
What should happen, IMO, is that individual parts of the RV are tested on the factory floor and there should be a QC procedure after delivery at the dealer lot. Between those points, any failures that are redundant should be reengineered so that the component in question has almost a "Zero" fail rate. All of this takes $$$$ and no one is willing to fork it over.