The phrase "sliding lid" refers to a cover or top that moves horizontally back and forth, either on a track or by sliding on a surface. Full definition
To dispose of a diaper, simply slide the lid and drop it in. (followmum.com)
Apart from the color, this one differs in that they did away with the flip - down center consul and replaced it with a spacious box with sliding lid. (autolist.com)
Also, a new sliding lid for the cupholder and an additional storage compartment has been added. (paultan.org)