Yup, big cut out required and yup, a cover panel is available; a look on Google's image search should bring an example up.
A point of note is that the cover panel is designed to fit the cutout for the OEM Seat towbar. If you fit an alternative towbar, you can still use the cover panel, but the cut itself may be slightly different and you might end up with an odd square to one corner that had to be cut out but that the panel doesn't cover fully, if that makes sense.
R.