For example, a search for "ca7112b7167c15e621412c0fbc0a6c97" brings up the URL "https://www.premierclearancecenterofstbernard.com/inventory/...", which has a gallery of vehicles at the bottom whose image names are of the format "9b362510c100095f02cf3cad9e365ea6.jpg".
I assume something inside the Google black box is saying "well, there's no exact match but this site has a bunch of strings with most of the same characters, so here you go".
Edit: And to add to this, I'd surmise that the reason you see a lot of car dealerships in these results is that they sell a lot of one-offs - instead of having a list of SKUs in inventory, they sell a unique vehicle just once, so the inventory systems need to account for that by using long strings as item IDs and the like. Also there's probably a limited number of inventory systems out there, so a bunch of random dealerships are probably all using the same one.