Spotted this on reddit the other day. Poster recently imported this car to Canada from Japan.

Has anyone ever mounted their AFM post turbo as seen on this car? Can't say I've ever seen it done like this before. Not sure what tuning implications it would have

 

it used to be pretty common, it does a couple of things.
first, having the AFM in front of the turbo is restrictive, and changes the p/r. if you put it behind the turbo its still a restriction, but it doesn't change the p/r
two, it removes a bunch of places to have vacuum leaks