There is a lot of speculation out there that the Model 3 will have a steel frame and aluminum body panels. The below questions make that assumption. Are there any metallurgical experts out there? A LOT of road salt is used around my parts so I love the idea of aluminum body panels. If I could afford even a CPO Model S, I would be heading that direction due to the aluminum body. Cars older than 12 or so years generally look like rust buckets here and nicer cars often hibernate in winter until the salt is washed away by spring rains (I do that with my bicycles). I am under the impression that joining steel and aluminum components must be done in a specific way so as to not exacerbate corrosion, but is this something that is fairly easy and cost-effective to work around? Additionally, what sort of rust protection could/should be done to a aluminum body, steel structure Model 3 such that it will continue to be safe and in one piece 20 salty years after delivery? Thanks for your input!