Was thinking of that. But it's a lot more hassle and weight to do that. And the underside of the ek9 is surprisingly flat. I've lifted the exhaust up into the well as high as possible to help with that.
Its mainly the lower arms at the rear and the bumper that's causing the air to slow going underneath.
Obviously having it flat flat is the best but I can't be arsed with it. May mess about with a rear diffuser and try and extend it towards the front of the car as far as poss.