I think the late 80's Volvos are among the best, longest lasting cars built. Period. But only their four cylinders.
Look for a 240 or a 740. My relatives have an 86 740 GLE that as of Christmas last year was just shy of 400,000 miles. Original engine. at around 350,000 miles he finally put some money in it - a/c, rebuilt front suspension, tranny rebuild, valve job. Virtually nothing has gone wrong.
I do know definitively that Volvo's are the longest lasting cars on the road. This is measured I think by Polk, which determines the longevity of a car by vehicle registrations. This is also the same service where Ford (or Chevy?) makes the claim that their trucks are the longest lasting trucks out there.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".