Just in the process of doing my 30,000 km service myself. Here's the procedure I used on the air filter.
I know it's obvious, but some may need a little encouragement to have a go.
Can others check their owners manual vs. the  service passbook and see if the owners manual says change every 36 months, the service passbook saying change every 24 months. Have others had their engine air filter changed every 12 months, was the old one dirty? The cost of the new element was AU$29.95 (those in the trade must get it for less) it took a minute to replace. Is it itemised on your bill? What did they charge?

https://sites.google.com/site/instroe/i30-crdi-engine-air-filter-replacement

[Shambles]

Further discussion here