Finally checked out River Motor Cars (Racine, WI) after seeing their lot on my commute for months. They keep around 57 vehicles, mostly hybrids and EVs. They were totally fine with my mechanic doing a once-over, which honestly settles half the trust question.
Lot address: 8692 Greenway Pkwy, Racine, WI. Visitor parking: Front-lot customer stalls facing the office; overflow on the side street near Racine lot gate.
Paper side: licensed with the state (looked it up), about 75% of stock has title in hand per the office, and they offer a 3-month/3,000-mile limited warranty.
Overall: good people to deal with. 27 years in business around hybrids and EVs, doc fee $599 and it's on the window sheet, no games. I'd send a family member there.