Simple question about a remap.

Given that the 1.3 in a swift makes 90 i am prepared to accept that there is more hiding in the jimny and the convoluted air pipe that goes in the wing would be one candidate so a hole in the air box could be an option. Also it being under the box it's not like pulling directly from on top of the exhaust manifold.

As for extractors and other traditional things they always have helped a little. Though I always thought that port matching the manifold and head in and out was a better use of time.

Looking through and it seems superchips offer a allegedly dyno proven 9 hp and 13 torque and I have at least heard of them.

"I find this quite interesting, firstly, it suggests that the factory intake is quite restrictive, and secondly, it flies in the face of conventional wisdom as such an opening would be a source of "hotter" air drawn from under the bonnet, rather than the cooler air from the fender well area"

Yes the standard intake is via some peculiar pipework in the wing that is restrictive. But to your second point as standard air is drawn in from the engine bay, just a few cm in front of the air box so intake temperatures would be the same.