Plastic on back of new dishwasher question

Hello

I recently gave u on repairing an old CDA dishwasher. Because of the amount I spent trying to get that right I have had to plump for the cheapest on the market: a Currys Essentials model (integrated). Compared to the CDA it is obviously made with cheaper materials.

I may have made a mistake with fitting. On the back of the dishwasher there was a sheet of what I can only described as sort of corrugated plastic. I assumed it was part of the packaging so pulled it off, which exposed the metal back of teh washer. However this plastic sheet was fixed to the machine through two of teh screws in the bodywork, which makes me wonder whether it actually should have remined on.

I looked at the old CDA and the metal back of that is covered in a kind of rubber that is glued to the metal – much better quality.

I’ve installed this Currys one now and would rather not have to pull it all out again to put this plastic sheet back. Any ideas what it is for and whether I need to put it back on?

Cheers