Depends on the OEM, but generally late-2010s is when it became more ubiquitous.

Any car with an infotainment system is probably a "risk," but especially '20s cars with features tied to apps are the real vulnerability here.

I have a 2012 VW Golf 6 and it's still ok. You can connect your phone via Bluetooth, but it acts more like a BT headset. It can show a contact list and caller ID, but that's as far as it goes. Maps can only be updated by buying a special SD card from VW. The car itself cannot connect to the Internet at all. It can read mp3 music from USB drives and SD cards. It also has a cd drive, and radio.

I'm quite happy with what it has. I know WV isn't very popular in the US, but it's common in Eastern Europe.

There are EV conversion kits available, so it is possible to turn an old car electric. They won't have the storage capacity of a natively electric car, but it is an option.

Unless it's a classic, don't. Just don't.

You'll be forever fixing and tweaking it and the integration usually sucks.