As far as the cars go, there are several things that come to mind.
A car could be used during a crime in another state and hid in plain sight in rural Ohio.
A car could be used during a crime in Ohio or another state, sold cheap, and scrapped out in hours.
A car can be reported as stolen for insurance or to get out of payments and hidden or scrapped out.
Any of the above cars could be brought to another state and sold at an auction.
Selling car parts in Ohio is basically illegal unless you have a licenses to do it in Ohio.
Getting caught with parts on a car that were bought illegally will result in the parts, possibly the whole car, being confiscated.
A salvage title or possibly a clear title can be obtained for a car not picked up or repairs not paid for after a period of time.
Personally, I don't see cars bought at auctions to repair and resell as being a high dollar business. I see a lot of cars that look like they came from high end used car lots get sold as scrap. Legal salvage
yards seldom keep cars over ten years old now. They get crushed and sold for scrap. A car can look like new but used parts can't be found these days...
Detectives trained in auto theft (it is a highly specialized area nowadays) and it involves not only theft deterrence, but trafficking in RFI key duplicators, defeating locks and electronic hacking, theft rings shipping offshore, VIN altering, etc. The insurance industry often partners with and helps fund auto theft operations.
Cars have hidden VIN locations, as do stamped parts, ECUs, engines, etc. One thing they could be attempting is to see if the secret VIN imprints match up with the visible VIN. The secret VIN locations are changed and updated to law enforcement. The locations typically are not shared with the general public.