That is PPF Paint protection for rocks to save your paint. It is not metal! That is a Plyable plastic film that its applied. In the front they used to refer to it as a clear bra!
Contact Toyota directly. Not the dealer the Manufacturer. I would seek legal action if they are not fixing it but you have a Warrenty this most definitely will be covered!
I have the westcott it is a small lift in the back and basically and leveling kit in the front. The ride is still very smooth with it. If you want a full lift so far the best one is King but it is a grip of money!
I am looking at this as an option. I have a receiver with a ball. This provides some protection should you get rear ended and I think it may cover the opening which will be left open on the half cover.
FYI Premium is the suggested octane. However, this is not required! You can run unleaded and you will not notice a difference! I still buy Premium but this is for optimum performance.!