Hidden for nine years
I've just checked one of the several cheat sites and it says that EVERY Lotus Esprit Turbo Challenge features a hidden game. POD can be found indeed by typing in "CU AMIGA" as your name in the selection screen of Lotus III.
This means that my copy of Lotus III features one of the most addictive Shmups ever and I was never ever aware of it in the past 9 years! Aaargh!
* knocks head to wall *