Mine is installed in the middle. The LATCH systems goes through an opening in the armrest. Is detailed in the owner's manual but essentially you slightly lower the armrest, fish the LATCH through than down the back of the seat to the anchor point in the middle which swivels.

I don't quite remember if the center seat has dedicated anchors for the base or if I simply used the inner anchors from the two side seats.

Let me know if you still have trouble with it and I snap a couple of pix tonight.

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