Drove my 2015 through 4 winters in West Virginia. Paid zero mind to road conditions within reason. I bought the car to enjoy and I did. Not one spec of rust as a result. I kept it clean as often as possible in the Winter/cold months. Rinsed the salt off ASAP(within reason) but sometimes it was just damn cold or I didn't get it rinsed for a few days. Not saying they don't rust but I am saying mine never did, not one bit.
Well, I truly hope it wouldn't rust in under 4 years!! Cars generally don't rust that fast - not even these Challengers! Most modern cars don't rust even after 10+ years - even when driven during the winter (my last few cars haven't had any rust - and they were 12+ years old and I live in PA and drive them year-round).
However, a lot of these Challengers have been shown to have rust-through issues MUCH sooner than most cars, which is the point - like in as little as 5 years - which is unacceptable - especially because people generally take better care of these cars than most daily drivers. Also, since they rust from the inside out, it doesn't matter how good you take care of the exterior surface.
You initially notice this as bubbling paint in front of the rear wheels.
If the issue wasn't addressed for the 2015+ model years (it doesn't seem that it was), I expect that we'll start seeing the issue in 2015+ models in the next year or two.
Just finished my first two mods on my new Scat Pack Challenger. Window Tint and Vinyl Side Stripes. Owner of the Tinting Shop did it all and made a video of the striping process as he went along.
Hope the link works.