Oh, for goodness' sake! Please, do not treat this like a joke. Do as k1ooo recommends. You are not dealing with amateurs; the criminal rings behind this scam have been practising it for years, and are adept at extracting every possible drop of blood from your dessicated corpse, so to speak.
People in general have no idea how much information they give away. There is a reason why cold "psychic" readings are convincing; people leak information, and they don't even realise it.
DO NOT ENGAGE.
There is also a reason why "name, rank, serial number" is the only information a captured combatant / military person is instructed to give. Engage, and subtle bits of data about you spill without your even being aware of it.
DO NOT ENGAGE.
DON'T.
DON'T TRY TO BE CLEVER. DON'T TRY TO TAKE THEM ON. Unless you are a skilled and highly trained cyber security expert, you cannot stay in the shadows and poke a stick at the bear. DISENGAGE.
Confirm nothing. Deny nothing. Either reaction will give away pieces of a puzzle. Non-verbal reactions will give away pieces of the puzzle. DISENGAGE, and don't contact anyone selling any sort of vehicle for well below market value. Even the initial contact gives away information about you.
Reinforcing what's already been said - these scams are not just about the vehicle. It's not just about the money. Your vulnerabilities can be exploited and your identity can not only be stolen, but used as part of ongoing criminal activity. That means that mortgages can be taken out on your property/ies, loans can be taken out in your name, bank accounts for money laundering can be opened in your name, and on and on it goes.
