Updates will be sent out via email along with instructions, I record all customer emails for this purpose.
There is a new update available from 29 June but I have not sent it out since no one has installed their units yet. I will do so in a few days, but it is worthwhile to try the firmware that comes with your unit first and compare. This new update focuses on DVD menu improvements and speed improvement when switching between programs (like nav / radio / SD / BT). These improvements are quite noticeable. Currently Audiosources is bringing out updates more than once a month.
As I said, it is unclear right now whether DAB+ will be a chip or plug-in, I will have definite information when Audiosources finalises their solution, but I do not want to make assumptions now and risk misleading. They are however chasing a plug-in module as first preference.
I am happy to answer all questions in this thread as I think it is useful to have all the important information together in one place for the public. I will update OP periodically to reflect new information.