I have a 21 month old, and 9 month old twins who all (obviously) need to be in rear facing car seats. I drive a 2009 Mazda 5 which has 2 captain chairs for the 2nd row & a 50/50 split bench for the 3rd. My 21 month old is currently in a Graco 4ever 4-in-1 behind the driver seat. I'm needing to upgrade my twins to convertible/all-in-one seats as they are outgrowing their infant carriers. I'm so lost at what seat would fit/install best in the 3rd row. I'm looking to stay around $150 for each seat but I could go a little higher if need be. I need some advice because I don't want to end up ordering a seat that doesn't fit correctly. I'm also lost at what carseat configuration would be best. Should I keep my 21 month old where he's at? Should I try the 4ever in the 3rd row with my twins in the 2nd row? Please help this lost momma out.