Now that you've talked OP out of it, I need someone to talk me out of it, too.
I mentioned to DH last night that there were studies showing that the Swedish seats were even safer than US rear facing seats... I said "Tell me that the seats we have are safe enough and I don't need a Swedish one" and he says, "Oh, you probably do." (facepalm). He's no help at all.
He's concerned about the legality, but not about the money. He'd buy me a Foonf if I wanted one, too.
DD is 30 months old, and 37" tall (mostly torso; 3T shirts and 24m pants), 35.5 lbs (naked weight). She's got a very unpredictable growth pattern; she was tiny until a year old, caught up by a year and a half, and was big by two. I'm not confident that she'll make it to 4 RF in her Radians, but she has plenty of space over her head for now. Her shoulders just made it above the 4th harness slots a few weeks ago.
I need another car seat like I need another hole in my head. I'm frankly kind of disappointed in DH for not putting his foot down and ending my obsession with having a Swedish seat.