Is it worth it?

Okay, so a couple of my carseats are set to expire in the next few months. I (obviously) need to replace them.

I just bought my 14 mo. old a Combi Coccoro that she uses RF in DHs car (DH drives a Kia Spectra, so a tiny car) and we have a Radian 65 in there for our DD1 who will be 6 in April. She is currently 42lb. and 3' 8 1/4" tall (so...40 1/4" tall?). Our DS is in a Wizard, and will be 4 March 28 (1 week before DD1 turns 6). He is currently 36lb and 3'3" tall (so 35" tall?). In my van I have the 14 mo. old in a Marathon RF. It expires in May. We purchased this seat new for DD1, and it's been used for her, our DS, and now the baby (so I'd say we got our moneys worth LOL). DS is in a Britax Boulevard and DD1 is in a Recaro Vivo Lite (in Blush). She sits appropriately in it, and actually fits very well in it.

What should we replace the Wizard and Marathons with? Is it worth it to buy DD1 a Radian 80XTSL at this point? Or is she going to outgrow it in height too quickly? Maybe a Graco Nautalis? What should we get for DS? We can put his Boulevard into DHs car in place of the Wizard, so we'd be able to fit something into my van. A Nautalis? Radian 80XTSL? What about the baby's seat...the Marathon. I have 2 covers for it, so I'd hate to waste them...but should i get another Marathon?

I drive a 2001 Dodge Grand Caravan w/ captain's chairs and 1 bench, and DH drives a 2003 Kia Spectra Hatchaback.

Thanks!

Well...

If you want to harness your DD1 then I think the Nautilus is the way to go unless you want a Frontier. I think they both have pros and cons, but the Nauti is just so much cheaper and easier to install in more vehicles. You could just use the booster.

For your DS- I think a Nauti would be good there too. You could buy one for your DD then use it for DS when your other Britax seats expire and you need it so you only need to buy one seat between them.

For DD2, hmmmmm. Well, I think there are some good used MAs on swap. That would probably be a good deal if you want a Marathon since you won't use 6 years, but that Flora RN is very pretty. If you got it then I could lust after it. You could sell your covers if you decide to not get another Marathon. If you love how it works RFing and FFing it's a good option. (You have TAs, right?) There are tons of newer options for her RFing depending on your preferences. The My Ride has some pretty covers too, but I'd make sure you like it FFing before you get it. You could look at the Truefit.