just joined the forum, main reason was to say thank you to the OP for such a concise and accurate description of how to change the filter, and echo everyone's comments about what a right pain it is to change.
I did mine yesterday following the instructions to the letter... got to the bit where I needed to remove the struts and though "surely not, not to change a filter, I'll see if I can work round..."
60 seconds later, I took the struts off.
If anyone else is considering it, points I'd share are:
1. The air filter housing on mine has "semi captive" bolts in it, semi captive because they're housed in a little plastic sleeve that will pop out- be careful with the last two at the back.
2. Watch out for the the tabs on the underside of the windscreen plenum, when refitting, can get stuck and bend. Oops.
3. I purchased new bolts for the centre and the turrets, part numbers for my 56 plate 330d
B07.14.6.954.965 - centre bolt, £3.13 each (July 12). In the parts catalogue at the dealer this looks like a normal headed bolt, but the one supplied is an EPL/female torx one.
B07.14.6.963.730 - turret bolt £1.63 each (July 12)
In the grand scheme of things not too bad. I purchased new ones because the spec for these bolts is two stage tightening.
Centre bolt 100nm then 100 degrees (per Haynes book of lies)
Turrets 40nm then 60 degrees
And wasn't prepared to put in pre-stretched bolts. Make your own mind up on this though, I erred on the side of caution.
Al in cost me £30 to do (filter and bolts). Bargain. 7mpg difference already, that's with the bike rack on top. :-)