The last reply about Norwich Union and their Open Policy was nearly a year ago and insurance generally for young drivers has changed significantly over the period. Google search Open Policy from Norwich Union the only real reference is this forum thread and a few oblique comments which say that Open Policy is excluded from quoting software used by brokers.
I had doubts that it was as the Norwich Union personnel made out and I was not convinced that they really understood what they were saying, nor that they should have been making such comments in an open forum.
I wish you luck but it will be a challenge to get a decent quote on the car specified with your age and experience. From what I can see Open Policy from Norwich Union seems to have disappeared, but would be interested to hear from anyone who knows otherwise.