Radiator protective grill fitted internally.

[neil-g8km6]

When this hot weather subsides I am going to fit a grill behind the front bumper, which IMHO will look much smarter than the Zunsport version fitted to the outside. I did this on my Boxster after removing the front bumper, however, on the Alpine i am hoping to get access by just removing the front section of the under tray.
Has anyone previously found access to the radiator and if so, was it by removing the front under tray, or another method?
I will post a write-up along with photos.