Around here in NE Ohio steep graded driveways are all too common where the parking brake is really necessary - but I was also always taught that when it comes to the emergency/parking brake - "use it or lose it". The point being that parking brakes do not like to sit and go unused. It is not uncommon for points in the linkage to get so corroded over time that when you do need it something may not work right. I use the auto setting on my Pacifica so it sees daily use. If there is a problem with it hopefully it will be apparent, and thus addressed, before I have an emergency situation where there is an issue with the hydraulic brake system or encounter a steep hill that requires its use.