Start with what the Audi A3 8Y is: a car with diesel engine, from Audi. What it meant takes a little longer.
Under the skin
The engine is diesel engine. On the scales it comes to 1280 kg. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
In context
Nearby in the Audi catalogue sit the Audi 200 and the Audi 225.
Owning one today
EPA combined economy is 31 mpg, about $3,300 a year in fuel at the EPA's assumptions. Condition, mileage and specification move any single car a long way from a headline figure.