340i
+1y
nice. so you're going to have a fully enclosed bed? as far as airflow to the filters goes, being that the whole underside is open, adding a scoop will probably not have any effect on performance. personally i would have either just attached the filters straight to the turbos, or just have one bend on each, a short pipe, then the filter (so there'd be one of each side. if anything, you may actually gain power, due to the shorter intake from filter to turbo. if you wanted to you could box those areas off, to minimise heat transfer from the nearby turbo, but with the massive air space you've got i don't think that would really be needed either.
either way, the setup looks like it will work fine.