We moved my 2 1/2 year old from an infant car seat that clicks into a stroller to a Graco 4evr dlx that is rear facing about a year ago. The very first time we took her in it she complained of her back hurting and threw up in it. She complains of her back hurting every time we go anywhere, even short trips and has thrown up 4 times now. She never complained or threw up in her old seat and had never thrown up ever before that first time. I'm not sure what to do about this but I hate to see her sick and I can't keep cleaning throw up out of the car seat. Anyone dealt with this?