Ok so I've googled for hours trying to find this video again with no joy, but I feel I'm closer now that I've found this glimpse of it.
(at 21-22 seconds in).
I recall it was a Ford owner who built this warehouse looking garage from scratch using recycled building materials and it looks like an old factory as a result.
I'd love to see the full episode again as it's my dream form of workshop / garage.
Not sure where the garage is, but I have a feeling it's out Lilydale Victoria sort of direction.
*Edit think I found it, but I'm sure there was a segment where they talked about the garage itself.