Well this is what I did, it was all straight forward. AU$41.90 for a Ryco Z707 filter and less than an hour to fit it. (1/2 hour next time)
https://sites.google.com/site/instroe/i30-cdri-diesel-fuel-filter-replacementI also contacted Hyspares to see if they were going to offer a cheaper alternative for the diesel fuel filter. The reply was that they hoped to be able to revise the price of the i30 fuel filter in the near future.
I compared the Ryko and the Hyundai side by side, very similar apart from the text on the outside, looking through the holes into the filter it looked the same to me.
I'm sure I read on the Ryco website that using their filters will not null your warranty. Either way if you're doing it yourself you've voided the warranty anyway. As you will see in the document, no evidence of water or containments at all in the original filter after 30,000 kms. In my case it was a waste of time and money, maybe different for others though if they got a poor batch of diesel.
Anyway - enjoy, give it a go, hope you can use my procedure to prep for your own work a little better.