best "to buy a really old car that isn't super-connected"
Car companies are actively trying to retro-fit this stuff into older models too. I took my 2010 Volkswagen in for a dealer service a few weeks ago, and when I went to collect it I was told "We've also given you a free* upgrade called 'VW Connect'"
Basically a VW-branded OBD bluetooth dongle that would pair with a free* VW smartphone app. One of the features apparently was that it would sent engine diagnostic info to my nearest VW dealer in the event of a fault and other "wait....what?" items. I took the dongle back off and it's sitting in the glove box for when I eventually go to sell the car.
* You know the saying at this point I'm sure