Not sure if those mudflaps will stop the front of the rear arches from recieving damage as that'll happen when stones etc get kicked up under cornering. The GT does need some form of protection though as I can see some pitting on my arches after only 17k, though don't know if I want to put that sticky stuff on it never looks that good, my friend has it on his elise and it looks rubbish.
I'll probably look at extra paint/laquer protection when I tidy up the car after a year of b-road blasting, first birthday soon, so it could do with a treat