Here is a short list of possibilities that might help you determine. All or none may help in your specific situation
For cars missing their door/warranty tag?
- Buck tag - if the plant your car was built at used them
- Buildsheet -
- Owners card -
- Dealer - emblem, decal, license plate frame, key fob (of course there are cases where the ordering dealer was not the dealer the car was delivered to but this is unusual)
- Stickers/decals - often found on windshields. Can include state inspection, emission or even parking for schools or company. Old gas station service stickers also fall into this category.
- Engine equipment - open crankcase or closed can at least be used to eliminate a few or allot of DSO's
- Trash - Items found under carpet, seats, in glove box, console that may provide a city and state .
- Of course any paperwork found in or provided with the car can provide clues
Just some possibilities