I'm guessing the Fiesta also has better brakes, uprated safety features etc...so you probably wouldn't wrap it round a tree, unless you were driving like a t**t...in which case you deserve insurance at £3k.
Simple ways of getting cheap insurance:
Be the named driver but put parents, siblings, friends etc as additinal drivers
Pass plus (not everyone considers this as a reason to decrease insurance)
Get an insurance group 1 car (http://www.parkers.co.uk/cars/advice/car-insurance-groups/?ig=1)
Drive safely and build up your no claims
There are no tricks really, unless you lie to the insurance company which is never good if you need to claim!
I jut swapped from a 1.2 16V bravo to a 1.8 16V bravo and my insurance only went up by £140 for the year![]()
from what you've put after I assume you mean policy holder