I've owned a bunch of BMW's. They were all unibody. Less nooks and crannies for salt to sit.
A body-on-frame vehicle has that steel frame the body is sitting on. That steel frame is more susceptible to corrosion, as there's lots of places for salt to just sit and work it's destruction. That's true of frames from every manufacturer.
Wash the vehicle, especially the undercarriage, at least once a week in winter is my advice. As others have said, parking in a warm garage when the vehicle is covered in wet salt, will speed up the corrosion.
The salt brine they use is horrible for vehicle longevity. I've been dealing with it all my driving life. I am really giving serious thought to moving somewhere where snow, salt, ice, and rust is a bad memory.
A body-on-frame vehicle has that steel frame the body is sitting on. That steel frame is more susceptible to corrosion, as there's lots of places for salt to just sit and work it's destruction. That's true of frames from every manufacturer.
Wash the vehicle, especially the undercarriage, at least once a week in winter is my advice. As others have said, parking in a warm garage when the vehicle is covered in wet salt, will speed up the corrosion.
The salt brine they use is horrible for vehicle longevity. I've been dealing with it all my driving life. I am really giving serious thought to moving somewhere where snow, salt, ice, and rust is a bad memory.