If I want to submit a forum post, I can request a preview of the post before I submit it.

I cannot see how to get the same preview of a review.

I just submitted a review and saw an extra newline in one para. I wrote the review in an offline editor and then pasted the whole lot into the review form and no such error was visible at that time but i guess that it was masked by the screen widths or something.

A preview mode for reviews would allow reviewers to see exactly how their review appeared before submission.