DD is only 6moths old but on the 98th centile and getting close to being too big for her first car seat. Having read the research I'm not happy putting her into a forward facing seat but finding it almost impossible to get a rear facing one for under £350 which we really can't afford just now (just bought a bigger house, about to move. In a couple of months it wouldn't be as big an issue but I'm not sure we have that long)
Her current seat (mamas and papas Aton) is suitable up to 13kg but she's already well over 9kg so big enough for the next size up, her head isn't over the top yet but won't be long until it is.