Why thank you for finding these for me. I admit, I searched around a bit on Toyota's and Honda's sites and found no such warnings - just generic "make sure to wash your car every couple weeks." It's quite remarkable that you were able to pinpoint this information in such a short amount of time.
So, in the end, would you agree that the stainless steel finish is no more resistant to damage than a typical car? It's no more rugged or durable?
