I would agree with Backpacker on this one - it is complicated.
Your non-airtight cabin will have airways to the outside.
If they are predominantly forward-facing, (like the front of a pitot tube), you would expect the cabin pressure to be above atmospheric.
If they are predominantly sideways-facing, (like a static port), you would expect atmospheric pressure.
If they are predominantly backwards-facing, you would expect sub-atmospheric pressure.
In reality the flows will be rather complicated, so forwards and backwards will be hard to define, but already we can see there won't be any simple rule.