Finally checked out Summit Car Lot (Lincoln, NE) after seeing their lot on my commute for months. They keep around 67 vehicles, mostly work vans and fleet vehicles. They were totally fine with my mechanic doing a once-over, which honestly settles half the trust question.
Lot address: 2337 Fleet Way, Lincoln, NE. Visitor parking: Front-lot customer stalls facing the office; overflow on the side street near Lincoln lot gate.
Paper side: licensed with the state (looked it up), about 100% 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. 21 years in business around work vans and fleet vehicles, doc fee $399 and it's on the window sheet, no games. I'd send a family member there.