The car is so low to the floor that even the ultra low jack I have will not get under the front, so I had to jack the wishbones up and drop the car onto bricks, then get the jack under the front. After a lot of measuring and re-measuring, I set the front ride height to 110mm, and the rear to 130mm. The jack now fits under the front ok too :)

I am not to worried about it for now, as it will all be re-done when we have a proper cornerweighting session on the car. The car looks a lot more drive-able at it's current ride height than it did before.