I don’t want to alarm you but you should get the undercarriage checked by a competent mechanic once in a while. If you don’t do your own oil changes, then you should search out a highly regarded mechanic to do your oil changes and he can check the frame members at each oil change.
Some of the suspension mounts hanging off the frame rails can rust off. If you catch a suspected area soon enough, they may be able to salvage it with a welder. They may also be able to slow the rust down some too.