Ian,
You can see that the vehicle is essentially a rectangular box viewed at mid-height from an oblique angle, hence my restriction of verticals in the perspective requiring only two vanishing points.
The only known problem with the procedure described so far is, where does one nominate the direct face-on view to be ?
Effectively, this was the camera axis when the photo was taken.
I have spent some time exploring the image, but cannot confidently nominate the axis position.
Attachment 355532
John