Those are more or less rigid and you still have to fix them to the body if they don't line up with the bumper irons. I have seen them use on a Simons rear box.
Maybe re engineer one of these. Used on S40 II, V50 and C30 and Ford focus.
https://www.autodoc.co.uk/hjs/143604...UaAsocEALw_wcB
You can probably use the block type rubbers too.