i heard you have to register the car first. ( well rsowners concours anyway) not sure about other clubs and shows?. I was almost going to do it with my fiesta, but am just of to tidy it up, then thrash it round tracks. better to drive them then have em doing nowt.
If you want to see an example of fiesta concours check out
https://passionford.com/forum/general-car-related-discussion/257632-cleanest-fiesta-ever.html
all the best.