Longevity is the theme today. And hindsight is 20-20 vision. And I just realized that this question can be read either of two ways: A): What would you buy if you could go back to 1981, buy new and drive until today? And B): what 1981 model car would you buy used today, to keep going for another thirty years? Which of course might (or not) be the same car.
A couple of parameters: you’re going to be driving this car regularly (although not at huge annual mileage numbers), and the whole goal is to be thrifty, so no, a 1981 Lamborghini isn’t going to cut it. But I will grant you one Eugenian exemption from reality: rust doesn’t exist. But everything else does.