I remember when I first bought the XJ-S oil changes were every 3 thousand miles, plugs at 5 thousand (if the engine was running right). We are now accustomed, with current engines, to oil changes at 10 thousand miles etc. Well my Porsche Macan S went in for its 30 thousand mile service and I was surprised to find out the engine air filters were not changed. Note that car dealers never miss an opportunity to take money from a customer, and Porsche has refined that art to a new level. I asked the service advisor when the engine filters should be changed and he said at 80 thousand miles under normal use. The SUV does have massive air filters (there are two, see attached photograph) but the service interval is the longest that I have every heard of. Of course the damn things probably cost a couple of hundred dollars each, plus labor. (smile)
And yes I can install them myself, but I have learned that you never give the dealer an excuse to deny a warranty repair.