my colleague is 100% sure it was under rear seat (06 exi) ....... he bought it from my cousin. car was almost 100,000 km's and filter never changed. i scared him, if filter chokes, pump will die, so he got it done next thing.
in the thread majority say its under the fender area as you have shown
and 1 guy in the thread claims they never gave a filter in the later model
but it seems they gave 2 different fittings. under rear seat and inside fender area