I think they should know the current product; standard features, options, engine metrics, construction materials & techniques, and everything that a prospective buyer might ask about a new vehicle.
Knowing what years the FJ60's was manufactured isn't important to a new car salesperson. Hell, I don't even know the years the FJ60 was sold in the US and I certainly don't know the engine/transmission/options and all those details.
However, I know a lot about computers; history, lineage, options, construction, and all those things that are immaterial in today's market. A new computer buyer doesn't need to know that today's Intel processors derived from an 8004, 8008, 8080, 8086, 80186, 80286, and on and on.
IMHO, it is quite vain for someone to expect a salesperson to know that their FJ60 was sold new in 1983 vs 1979.
-B-