I drove a Rabbit Diesel back in the early '80s. It was not a luxury driving experience, but 48MPG highway! I didn't have much money and squeezing in a 700 mile round trip would let me visit my girlfriend over a weekend. Lots of miles in that car (mostly in the dark hours of the night, middle of nowhere, with Tangerine Dream blasting).

I doubt it would come close to passing modern safety standards, and I guess we saw how likely it would be for VW to make it clean enough for modern emissions… but it was an economical car to buy and operate. Here we are 40 engineering years later and all of the "New Small Cars With the Best Gas Mileage for 2022" have worse highway mileage than that 1980 Rabbit.