Where is the battery on a 2000 Buick LeSabre?

Answer 1

Answer
The battery is located under the rear seat cushion. To remove, place your hands in the "bite" of the rear seat-back, and the rear seat; pull the seat up and away from the seat-back. The seat will come loose and the battery can be accessed.

Edit: Thanks for this answer. Some observations for when I tried it: The "bite" is referring to the place where the seat and back cushions meet. Reach down in there, and give the bottom cushion a good upward yank. You'll feel and hear some snaps coming undone. You may have to pull from different places, i.e. left, right and middle, in order to get the whole seat to come up.