Was this used car purchase a scam? How?

Only most cars have bespoke connectors, that are harder to obtain than the illicit software, which can be copied and copied and copied… The connectors can be bought illicitly too, of course, but they tend to be expensive.
What really has my head spinning in this whole affair is how complicated you all describe the private sale of a car. You go to a notary for that kind of transaction in the USA? Wow. I never heard of that in Europe, i.e. for Germany, Spain, Belgium, France, Italy, Swizzerland, Luxemburg or the Netherlands I am pretty sure nobody does that. ID cards may be the difference. Wonder if it is that complicated in the UK too.
And car flipping is a business model? I can tell you I knew somebody who once tried that. It was a complete fiasco.

Not in any of the states I’ve ever lived in. I mean, you can get a bill of sale notarized if you want the ultimate in security, but all that’s been required for me is signing the transfer of ownership section on the title, and then submitting a release of liability to the DMV. And the release of liability has been technically optional, but a good idea in case the new owner is a flake and causes an accident before they register the car as theirs.

That is reassuring. A notary seems like overkill or expensive paranoia to me.

Sure, if you want to do it the easy way.

I thought my plan had a certain low cunning to it.

How formal the process is depends on the level of trust between the two parties.

Reasonable level of trust:
Many years ago, I decided to buy a new car. My secretary asked me if I would sell my current car to her son. So the three of us met in the parking lot after work, he test drove it, we negotiated for about 30 seconds (he was just a kid and probably would have agreed to any price I set, so I explained what it was probably worth and offered it to him at 10% off), we shook hands, and a few days later met at the credit union where he (or his mother) had gotten a loan and I signed the car over, handed over the keys, and got a check in return (which led to an entirely different contretemps with my credit union). Low calorie.

High level of trust:
When I bought my last car, I just outright gave my old car to my sister. One holiday weekend, I drove the old car up to her place, checked on the DMV site on the required paperwork, signed over the car to my sister, told my sister what she needed to do with respect to the DMV, and handed over the keys (got a ride back to the city with my other sister and flew home). No calorie.

Notary is required in Montana, FWIW. Kind of a pain.

Used to be required in PA. That was a long time ago and may have changed.

I contend that Bob did NOT see an ad for the car from Don and Dan, but just made that part up. The only evidence that the car is being re-sold is from him. He’s the scammer, looking for hush money. I don’t believe yet that Don and Dan are putting the car back on the market so quickly.

Notary required in Wyoming also. Very little expense, just helped my daughter buy her first beater car in a private sale, notarial service cost less than $10.

No notary needed in Oregon. If you do need one, check your bank. US Bank here has free notary services for customers.

As noted above, a notary here in the US is not expensive, and many banks provide one free. Hell, I used to be a public notary a decade and a half ago for my job, and I’d do it for free for anyone who asked. I don’t think I was allowed to charge more than $1 for simple notarization here in Illinois.

Missouri used to require a notary but hasn’t in many years. It wasn’t a big expense, usually done for free at one’s bank or credit union.

TIL that a notary is a different thin in Europe and in the USA. Notaries are expensive here

No, it isn’t.

All UK cars have a Registration Document (V5c) which shows all the car’s details, including the current Keeper’s name and address. You would be foolish to buy a vehicle without a V5c (and a service history) and proof of ownership such as a purchase receipt in the name of the vendor.

It’s easy to get more details by logging on to the Government’s website, which will confirm the ownership and MOT history, including mileages. Every year, after the first three, cars are examined and the details entered into the database, so discrepancies would show up instantly.

Once the sale is agreed, and the money transferred (cash or electronic transfer) you would use your phone to pay the tax and confirm the insurance, which you would have previously set up. The V5c shows:

  • Vehicle make
  • Vehicle model
  • Vehicle Identification Number (VIN)
  • Engine code
  • Engine size
  • Vehicle Registration Mark (VRM)
  • Date the vehicle was first registered (and in the UK)
  • Number of previous registered keepers
  • Colour of the vehicle
  • CO2 Emissions Rating
  • Taxation band of the vehicle

You send part 2 off to the DVLA to register yourself as the new keeper and the seller sends their part to confirm that they no longer own the car, and that’s it.

My first car was a VW Beetle. I discovered the speedometer/odometer was easy to disconnect, so I kept it disconnected.

When I took it for inspection, the mechanic yelled ant me. Although I’d reconnected the cable, my previous inspection showed the mileage and he saw I’d only put 8 miles on the car since then.

He didn’t turn me in, just told me to be more careful.

I thought most automobiles used that standard data plug for quite a few years, so any mechanic can read the diagnostic log.

I think by now most jurisdictions keep that information private in North America. Why make stalking or harassment easy? (What to know who the idiot was who cut you off in traffic, or the hot blonde in the convertible, or who had the easy-to-steal vintage vehicle, or where the ex- is living now? Maybe a public database with address isn’t the best idea…)

Agreed - that’s why those details are not public.

the OBD-2 connector and comms protocols became mandatory for all new cars sold in the US after 1996, but AFAIK this doesn’t interface directly with the vehicle’s odometer. You can get current speed and so calculate distance traveled since the start of logging via the OBD-2 connector, but to read the vehicle’s total miles, you need to connect directly to the odometer - and that’ll be each manufacturer’s connector of choice.

I might be misinformed, but I understood that notaries in Europe are closer to attorneys, in what they can do - that is, they can offer counsel about legal forms and such.

I am not sure what an attorney does in the USA, IANAL at all, but notaries in Europe are considered (or consider themselves) the crème de la crème of the law profession in the abstract. They do not work in tribunals (mundane concrete stuff), they work rather with documents (ownership deeds for houses, enterprises, and the such, but not mere cars, and also testaments). I do not believe that they do counseling work here, but I may be wrong. I guess @Schnitte knows all about that, I think I am sowing more confusion than helping to clarify the matter.