Dasher was the first Passat
You are correct. The Dasher was the first Passat. I owned one and was disappointed when it "only" got 40mpg on the highway. I bought it used when I lived in California. They were going dirt cheap because no one wanted to go near a diesel thanks to GM. GM took a V8 gas engine and turned it into a diesel with modifications in the late 70's/early 80s. GM single handly destroyed the market for diesel cars for over 20 years. People did not differeniate between GM junk and a well engineered diesel car. Now GM wonders why people won't go near thier cars.
By the way in the 80's all diesel cars bought in California had 10 year, 100,000 mile warranties, free, due to a law passed because of the GM fiasco.