The 1977 Oldsmobile Toronado is generally considered to be the first car to have microprocessor control.

But Ford's EEC was built around Toshiba's TLCS-12, the world's first 12-bit microprocessor, developed specifically for engine control, and might have been in cars produced prior to 77, but documentation is spotty.

So do you only drive cars built prior to the late 70s? Because sacrificing the enormous safety improvements just for a bizarre feeling of moral superiority is a really awful hill to die on. And literal death is a real possibility

Or do you not drive and never planned to buy any kind of car and thus your claim is meaningless?

TPMS (tire pressure monitoring system) is a coin battery powered computer inside each tyre of your car. They’ve been around for a couple of decades now. Even the lowest end cars have TPMS in each wheel. If you change wheels you need to go to a wheel shop and have them re pair (as in re pair wifi) the wheel with your car. I had to do this recently with my 2014 ford focus.

Anyway those are just four of hundreds of computers in your car these days.

I mean, "no microprocessor" means no engine designed in the past 30 years, because the fuel pump needs one.

"No antenna/modem I can't readily remove" might be _slightly_ more achievable.

That’s a very hard line