I have always liked the wooden coin holders. They look incredible on those special items. They also come in different designs, for coin holders or slabs.
https://www.lighthouse.us/collect-coins/presentation-cases/wood-finished-coin-cases-volterra/

By the way, does anybody know of display boxes for larger objects like the Doge Car? All the vinyl boxes I've seen on Amazon look cheap and fragile. I'm looking for something more, "museum-like".