My husband and I are expecting number three in Jan.  We have a 6 & 2 year old.  My 6 year old is in a graco nautilus car seat (not the booster style but still with the 5 point hardness) my 2 year old has a Diono Raidan rear facing.  I have a 2012 Malibu and we aren't planning on upgrading for at least another year or two (once we pay off my husbands truck) So my question is best infant seat to fit three across.  I'm going to buy a Diono booster seat for my oldest, so I have the two thin seats.  I've always bought Chicco infant seats, so I'm just wondering if that's the thinnest route.  Also I'm a little nervous having my 2 year old sitting next to a newborn so I'm thinking of having my oldest in the middle.  Just looking on some input/advice on having three car seats across.