At the risk of adding to this post out of order, George previously discussed the rattle of his sliding cabinet doors. Like many of us, I have copied quite a few of the methods and solutions that George has so graciously shared. Here's a simple one to add that has worked well for me (so far).
I go out on some pretty rough roads where everything bumps around. To stop the doors from opening and even flying out of their tracks, I cut some HDPE to put in the 80/20 slots where the cabinet doors are so that they don't open. The fit is tight so they don't rattle either; just the pots, pans, and all of the other stuff inside. Pics attached.
When I need to open the cabinet, I just pop them out using the ⅞" finger hole that I drilled. There are two per cabinet - one on the inner sliding door and on on the outer sliding door. Now I don't need to figure out some other type of locking system either.
Hope this is useful to some others out there and thanks again George for helping out so many of us.