REALLY sorry it was me that wasnt online for a while,thanks so much for all your replies,i rang the dealership and they got back to me said it couldnt be done because of legal reasons/didnt give reasons but i presume its the in case of accident thing.they also cudnt tell me if the isofix thing for back seat would fit(greatly trained staff they have there!)had a side on collision before and i wudnt mind the airbags didnt come on/only to be told i need to be hit head on!(great)So il come up with a solution,mite try a family friend who owns garage,see what he says.
Well whatever happens i wont be getting rid of my Mini,it was the first thing out of everyones mouth when i annouced i was pregnant!