Incredible

[ItsGreen]

Which engine have you got? All the ones I've ever worked on have been really easy, just open the box at the front of the engine bay.

Maybe I'm just being bitter because I've just changed the filter on my bike, which involves removing the fuel tank 

The B9 HDi has the filter to the rear of the engine, under the scuttle shelf. It's not great to access.

Which model has the air filter at the front? Apart from my first van being a 1.9d I have only had HDi engines and can't remember seeing any engine where the filter was at the front.

My 2.0 8v HDI has it at the front on the gearbox side, think it's the same on the 1.9's, long time since I worked on one though. 

[notsofast]

Yes my M49 (1.9 - early DW8) has it at the front nearside corner, and is v easy to change.  I changed mine last year while I had the air intake/inlet ducts off to access the radiator, resulting in being able to see the air filter, and it was suggested I might as well change it while I was mucking about around there. If I recall correctly, I just unclipped a couple of clips to remove the cover at the bottom of the filter housing, and the filter dropped down (the ducts wouldn't have to come off).