I'm sure everyone will be relieved to know I retrieved the cap just after Christmas, at one stage I thought I was being swallowed into the engine area, managed to go up and over the engine with my arms and grab it off the very bottom of the car.
If it happens to you, be patient get a good torch and have a good look.
I saw a young apprentice mechanic drop the oil cap of my Civic into the engine bay a few years ago; it took him half an hour to recover the cap and he had a ramp. He ended up removing the plastic cover underneath.
So, I was mortified when I dropped my oil cap into the engine bay of the same Civic this morning
. I found this thread and it helped me focus
The key advice for me was to "have patience" and a good torch [thanks @nelster
]. I put down a big piece of corrugated cardboard to lay on, scanned around with my "emergency" LED torch (not easy as I wear varifocals these days and the the Civic is very low) and eventually spotted the oil-wet cap glistening
I used a very long, fairly thick, piece of wire to hook the cap back. There is a hole in the bottom plate which I couldn't see, and was unaware of, but the cap fell onto the ground earlier and more easily that I expected. It took me maybe 15 minutes - quite a relief. Thanks guys