No, there wasn't any. Since this story, the lights clouded up due to the curing of the cyanocrylate, so I bought another 'perfect' one off ebay that was also cracked but got a refund and kept the light which I sealed from the outside.
I also bought a new ULO one for £185 from carparts for less. Now that
is perfect
ULO is Odelo GmbH's aftermarket branch and the ULO is clearly off the same line as the Audi originals, therefore theoriginals are Odelo.
I emailed them about the issue, but I'm yet to receive a reply.
I took apart the old ones, they are really quite beautifully made inside. It's a shame about this issue.