So DS is just 6 months and is a TANK. He is in 12 month clothes and his shoulders are so broad that he barely fits in the carrier he is currently in. I don't feel comfortable leaving him in this one. I can buckle it just fine but he is so wedged in there! What suggestions are out there? I started my research but my head is spinning from all the requirements/measurements/expiration dates on car seats these days. DD is in a convertible and since that is all we have ever known we have nothing to compare it to...we may just invest in another. What are your suggestions?