The quality is really good. No problems with painting as no preparation needed.
Its been on for a couple of years I think now and no issues whatsoever.
It doesnt quite cover all the area of the old spoiler at the very ends so if you look closely you can see marks in the paint on the bootlid. Not a problem though and if I had known before ordering mine, it would not have put me off. If you really want a show car finish, you could mount it and have the whole bootlid sprayed with the spoiler on.
Not that I am trying to put you off, just give you a heads up! The car looks so much better with it on and I would definitely recommend them.