I think they were put on the inner wing to avoid the heat effecting the coil...I should imagine under bonnet temperatures are significantly higher in a Wedge engine bay than a Land Rover...
Some heat reflecting material may help....I made a little jacket for mine...
It was on the same position on my Range Rover. Just seemed a natural place to put it.
I'm going to see how it goes. I always have a spare in the boot anyway. They're pretty much a service item. + it's 30 seconds to put it back on the wing.