It shouldn't be hard to find what you are looking for. Almost all the laptops that I work on have a 100% plastic housing. Even if some of the trim looks like shiny metal, it's probably just plastic.

Here's an example I found with a quick browse of the Dell website, i5 and 15.6" screen.
https://www.dell.com/en-us/shop/dell-laptops/inspiron-15-3000-laptop/spd/inspiron-15-3593-laptop/nn3593dxews#features_section