I know, it might not fit her well. I'm hoping it will, but it's likely that it won't.
I'm not too worried about it fitting in my car, it's in the 3 across thread in a 2009 Camry next to a RF radian and a Turbo Booster on the other side (Ours is a 2007 Camry, so the back seat should be very similar, if not identical).
I hope dd will fit in it well, because it would be nice to have one latched in and not have to buckle it in all the time. The Parkway SGL could do that too, but the arm rests look like they would be harder to buckle around. The Compass B570 can latch but still has to be buckled in when not in use (per the manual) which defeats the whole point of having it latch in IMO.
Are there other boosters that can be latched in that could be a better fit for her? Besides the Clek, I'm not spending that kind of money on a booster.
If the Monterey won't work for us, my back up plan is trying a Parkway SGL and seeing it that fits both the car and dd well AND if it's not a pain to buckle it, then after that going back to the Compass boosters, starting with the B570 (for the easier to use belt path and flip up arm rests).
ETA, I forget, can the nautilus be latched in booster mode? If so, thats an option too if it would be a good fit for dd and easy enough to buckle. I could use it later for ds when he's FFing so it wouldn't be a total waste of buying a combination seat just to use it as a booster.