I think that WildAuto mirror only lets you look wider (fine on a Disco as it's wider than a Triton to start with, i assume), whilst the issue for most caravan users is seeing into the space alongside - and behind - the caravan (the yellow zone in the diagram on post #12). I wonder if that mirror would fit on the end of a car wing mirror, rather than the top...

I like the EMUK mirrors, but they look like they go too wide - and are mucho expensivo too :-)

Yes, you can also put it on the side, making sure that it is as vertical as possible. I didn't put it like that because it seemed to stick out too much. But pay attention to the curvature of the mirror. He is made to eliminate the blind spot and therefore widens the vision horizontally, if you put it vertically you lose the benefit.