I have come across a link which seem to explain the setup better. I was doing it right but what the instructions didn't say was the if your starting point is say 396mm and you want to lower it by 10mm you would type 406mm. But then you look at it and think no i want to go 5mm lower again. So when you load vcds screen up again it will display still 396mm which confused me as I thought it would have stored it as 406mm as that was what I just entered.
So I then type in 411mm so that I get the full 15mm drop. Incorrect you don't!
Apparently that would only further lower the car by another 15mm. What should be entered is 401mm and this will lower the car by the 5mm you wanted.
Hope this makes sense.
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Audi A8 sport 3.0tdi Quattro, 19" wheels, 2tone leather, rear camera, heated seats, ami, Bose sound system, dab, xenon adaptive headlights, 4 zone climate control