It might work on a Festiva or Geo... maybe if you got 3 it would make a slightly noticable difference on an LS?I'm not really following the science behind how this thing is supposed to work.
so - IMHO - the most thing thing could do is act like a 'ram' scoop. the real question is - can this thing spin fast enough to push more air into the intake than it would draw in by itself. if not - then it could actually hurt airflow