do the back seats in a 2005 lay down

It would depend if your car had this option when originally sold. Look at the top back of the rear seats and you should be able to see a latching mechanism if they are so equipped. Often times only one rear seat will fold down, usually the passenger side.

I would say try looking for grey straps or knobs in the trunk, by where the passenger side trunk hinge is located.

I forgot to mention that some Malibu may have rear split folding rear seat and some don't. If there is a split on the rear seatback when you look at it through the trunk, then rear seatback do fold down.

Mine has a split in the backseats, but no levers to make them fold down..

The latches are in the trunk of the fold down on the right side at the top.

I can open my trunk

I can not open my trunk.

Why can't get my trunk I open