As you may know pre VE commodores don`t come with cabin filters, cabin filters can be a great asset for asthma sufferers pollution worry wort's and the cleanliness of your interior as it traps dust, pollution and pollen before it get pulled into the HVAC system, they have been common place on euro cars for a long time, yet Holden and ford Australia been built in a semi arid - arid dusty country does not come with them until 2006. for a bit of cheating here is a link to take apart he rain guard and get an idea of whats involved. Upgrade Cabin Air Filter Installing them requires. a cabin filter Many use fram CF8921 and CF8921a but this requires cutting to fit and can become messy. After some leg work I have found one that will fit almost perfectly. Citroen grand Picasso C4 van types will fit. carbon activated ones an be found here, you get 2 per pack. C4 Picasso Pollen Cabin filter C4 Grand Picasso Kit Automatic AC 47XG | eBay Using the guide in the link You will also need to remove the windscreen wipers just pop the rubber caps of the base and use a 13mm socket to remove. there will most likely be leaves and junk on the mesh so remove slowly and vac all the loose crud up. clean up the mesh and install it back over the top of the Citroen filter to hold it in place. refit guards and wipers. Job done.