Now for something completely insane MeowMix....
Carfax showed my VX spent it's entire "registered" life in Virginia and DC...I bought it out of VA with 64k, all stock. I didn't have it inspected (insanely stupid!), just pics from used car lot. Shipped it to AZ & took it to mechanic....no rust.....go figger (insanely LUCKY!)

Since VXs clearly move around the country quite a bit, here's some tips on assessing rust as you go forward with your search.
A good tell-tale sign of a possible significant rust issue on VXs: the front bumper support bar, behind the cladding. MANY owners have said it just rusted away to dust and fell off.

Another common area of rust: The license plate light unit on the rear, directly above plate. Several have had to redo it cuz it just rusted away. Deermagnet did a great overhaul/redo if it. After I read his I checked mine, and it DOES have quite a bit of rust.....so that appears to be an area especially vulnerable to rust.

Another comment on rust is the various bolts and screw heads in the engine bay. We often comment on these in pics. Don't think it's that definitive as a sign of a rusty truck, but certainly worth looking at on any one you check out. I have some lightly rusty ones right on top of the radiator/grill area, but we've seen some with severely rusted bolts.

I grew up in Penn, so I know salt and I know rust.....but the VX fever had blinded me and I hadn't yet read ALL the details on this site. Just sayin' you're right to be very cautious about East Coast cars, but, apparently, not all suffer that fate. Either that or mine was registered in VA but "lived" somewhere else.

On my recent "See America" driving tour, I got coated with some gray stuff in Colorado...I mean coated..... luckily RallyDude and MSHardeman knew exactly what it was and advised me to get it off! They spray the roads ahead of time with this variant of a salt product and you get it all over the undercarriage and everywhere else. too.