Which is narrowest?

[Wife&MomX3]

We have Regent for our oldest, and I used to think Id get one for our next when need be, since I love the Regent and so do DS. Plus, it's so cheap many places now. But w/ so many ppl loving the Nautilus, and the Frontier also being a possibility, Im looking for specs. Does anybody have the width dimensions for each of these 3 seats? We just moved dd1 to the back row of our Odyssey in her MA, w/ DS in the Regent, when she hit the RF wt limit on the MA. We cant use the 7th seat now. I doubt any of the 3 seats Im asking about (Regent, Fronteir, Nauti) are skinnier than the Marathon, right? Cuz if I cant use the 3rd seat in the back row no matter wut, I dont have a problem getting another big ol' Regent 2 stick back there next year. TIA!
(ftr, dd1 will be giving up her MA to dd2 when dd2 outgrows the old RA she's in, so dd2 can stay RF. None of my kids even made it to 2 yo RF in that RA, I wish I woulda known more about carseats when we bought it 4 yrs ago, wut a waste :thumbsdown: )

 

[firemomof3]

I don't know the dimensions but I can tell you from experience that the GN meshes much better with other car seats vs the Frontier or Regent.

 

[abacus2]

I don't know about the Frontier or the Regent, but the Nautilus fit in a three across situation for me where a Marathon wouldn't.