I wouldn't recommend it. What you can do is buy the original springs for the car. Not cheap but you won't notice its' 20mmm lower then stock cars.
Does this look lowered to you? (new VW original springs):

As you know i "built" my to be strictly OEM (every small part). So this is how they look like. And here is the part.numbers (the rear springs you have to order from Volkskwagen classic parts):
