Is the Plymouth Duster a fastback?

dmopar74 said

Fast back to me needs to have the trunk area open to the interior of the car, so a duster isn't a fastback.

Click to expand...

That would be a hatchback...
A hatchback is also a fastback, but a fastback must not be a hatchback.
Fastbacks came first.

In the 60s there were - nearly - no hatchbacks, but a lot of fastbacks.