DH just thinks she's "too old", not any good reason really - I've been delaying it since she was 2. And she's started noticing that other kids (friends, on TV) ride FF and she wanted to do it too. I guess the only legit issue he has with her RF is that it pushes the driver's seat so far forward in his car, but we had even gotten that to be manageable with the Marathon.
I can try her FF in the Marathon, but then I'd still need another seat. We are visiting friends with a MR in 2 weeks, so maybe we can try her in that and see if DH likes it. It will be a hard sell though, since I did just buy two Nauti's...
Couple thoughts here (non-tech not-quite-mom opinion);
1. Has your DH seen any of the videos/read any information on ERF? Here's a couple of recent articles that you/he might not have seen:
http://tinyurl.com/kuf9wo &
http://tinyurl.com/y8hao4q I would encourage him to get educated on what is the safest choice for your children - things have changed in recent years and all sources say that children should stay RF until they reach the limits of their seat, regardless of age (basically) and many seats have a RF limit of 35 lbs or higher now!
2. If the driver's seat is being pushed too far forward the first thing you should check is the angle of her seat - I assume that you don't still have it at the 45 degree angle necessary for an infant? If that doesn't solve the problem with his seat, I'm wondering if an install in a different seating location (middle?) might help, as she's old enough to be able to crawl into the seat on her own and all you'd have to do is reach over and buckle her up rather than trying to lift her in.
3. Re: DD seeing others FF, I would have a discussion with her reminding her first that her safety is the most important thing to you and her facing the back is safer. Also it seems that FF does make her car sick, so even if she wants to do what others are doing, if it's not comfortable for her that's probably a good argument to keep her RF - she's happier that way!
4. I'm not 100% sure, it depends on store policy, but you *might* be able to return the Nauti's or at least exchange them for something else. You might want to consider another convertible for DD (the MA can still go to the baby), whether that's a True Fit (RF to 35# I believe) or perhaps a new Radian XTSL which is RF to 45 lbs! You'd definitely want to try any new seat RF to see how it fits with the driver's seat and checking to make sure you can get a good tight install on it but if you can get a good install on either of these seats, DD will be able to stay RF longer, thus potentially avoiding the car-sickness issue altogether or at least putting it off for a year or more.
If you're unable to return the Nauti's, I'm sure that you'd be able to sell them - you might not get full price for them since they're 'technically' used, but considering how much use you've put into them you should be able to get practically all of your money back for them; if you haven't lost any/much money on the purchase then it's harder to use that as a reason to not buy something else. (You may find that you need a different seat for the vehicle DH drives vs the one that you drive if driver's seat position is very different.)
Last resort: I do agree with the PP who said to try DD FF in the MA. If she's not as affected in that seat, then you could try returning/exchanging/selling the Nauti's for a pair of new MAs - either keep DD in the current MA and put the baby in a new one or vice versa. Just make sure that whoever is in the current one gets a new seat before it expires.
HTH & good luck,
Melissa