Does back seat lay down for hauling?

No

Can't haul much in a 05 lesabre. Surprised this is still on the road..

No. You might have a trunk pass through to carry longer items such as skis or golf clubs. If you have a fold down center arm rest in the back seat, pull it down and look for a key hole. If you have that, the ignition key will unlock the panel so you can fold it down too. Your pass through will then be open. Hope that helps! Jim

just the tiny passthru