I know its not exactly an exciting topic but someone else must have had the same problems as me.
We have 3 kids, two on just booster cushions who are 8 and 6 and a third who is 22 months and too big for a baby/toddler seat so we need one of the seats of the type that has a harness built in but can later be turned into a highback booster. Now heres the problem, we went to buy one and the oh so helpful lady in mothercare says you cant put a seat on either side of the rear seat as the whelarch is in the way and you cant put one in the middle because none of them apparently fit properly, oh except miraculously the most expensive one in the shop!!!!
So what do other people find fits well??