Join Date: Jun 2006
Location: west of civilization
Unless the vehicle manual actually says "You cannot put a child seat in the center position in this car", it's fine to put the seat in front of a flop-down arm-rest.
Years ago, an Evenflo infant carrier made a rule against it (which they later reversed) and somehow it became urban legend and got applied to all seats. Not true.
Your car is a Canada special so unfortunately I don't have the stats on it, but a quick glance at my LATCH manual shows that no US Nissans have an arm-rest prohibition. I would guess the same is true of your car.
The True Fit is a fairly simple-though-complicated seat. LOL. It's actually quite easy, but it's more involved than the standard 'throw the belt throw the hole and plug it in' seats. It has lock offs underneath the cover for both LATCH and seatbelt installs (FYI, Nissan does not allow the use of center LATCH so if you do go with the center install, you must use the belt).
The cover is removable without removing the harness and very soft and plush. The harness is adjustable without re-threading. It has a taller top harness position than the Marathon, and a taller shell as well, so it lasts longer for both rear and forward facing.