I have weather tech liners in the front.
I do not have the sliding tray thing, but i have the husky rear cargo liner...it sucks. Nothing stops it from sliding on the carpet. Every time you slide gear around on the tray, or slide cargo in or out the tray comes with the cargo.
They need to add those little nipple things on the back side that work like cleats in the carpet and keep the liner in place.
I have not found one that does not slide with cargo....