The model years of 1978, 1979, & 1980 were transition years for GM
In 1978 the A body (Cutlass) was downsized following the latest trend
for American auto-makers. Contrary to some other information, the
Cutlass line, according to GM's own documents, still an A body until
1981 when it became the G body. The A body in 78-80 though, had
more in common with these later G bodies than the traditional A body.
I say these years are "forgotten" because they are currently, popularity
wise, the underdog of Cutlasses... occupying essentially the same spot
that the early 70's Cutlasses held in the last few years. As the owner
of a 1979 Hurst/Olds, it gives me hope for my own year, that these
other underdogs are finally getting some very long deserved attention.