I’ve pivoted and have it narrowed down two a couple of almost identical 2019 Limited Stealth Packages with HD towing. One is 14k miles. One is 18k miles.
The 14k miles Is $1000 less out the door but I’ve discovered it needs a Transmission valve group/body replacement (or so a service tech believes) due to shift hesitation and a driving rough feeling. Clean undercarriage.
The 18k started life in Canada and has signs of increased early with might be early rust/corrosion levels on the undercarriage. No other history issues. Pics below.
Is a transmission issue at 10-15k miles a warning sign to avoid a car?
Architect ...I sure wouldn't worry about that minor of rust. If some of it is exposed in places that you find visible, it's a pretty easy fix, if you want to conceal it. I don't imagine rust is too big of an issue for you in "non-coastal" Texas ...so it shouldn't get any worse than any other vehicle. As far as that muffler (or cat?) goes, those buggers get so dang hot, they're always the first thing to rust-over. I'd want confirmation that expansion in that formed-lip isn't leaking.
As far as that transmission goes, I 'spose it is a bit of a crap shoot; however, I gotta believe there are a lot of "over reported" issues with these 10-speed transmissions. I know I'm still getting used to the way it shifts. From my review, they never really go 1,2,3,4... thru the gears and instead go 1-3-5-7-9,10 from dead stops and then 2-4-6-8,9,10 when maneuvers (turns, traffic, etc.) never cause you to come to a full stop. It can make the transmission to feel like two different animals under acceleration (to me anyway). I could see how this could make some folks feel uncomfortable or like there's an issue.
All that being said there could be an issue for sure ...but even with 15K mileage, you do have another 45K of warranty left (or 4 years). Even though my '19 Limited was new, I still opted for an extended warranty (the Ford Premier). I'm not usually an extended warranty person ...but these dang cars have gotten so expensive, I usually get one on vehicle purchases.