Again with vehicle technology marching on comes increased service life for many components, this is never truer in the case of spark plugs often not requiring replacement for 20 thousand miles or more, consequently they are changed at full or major service intervals. However there is absolutely no harm in taking them out for a quick inspection and should one plug look radically different from its neighbours further investigation would be a good idea.
Modern cars tend to run much cleaner so the incidence of a sooted up or oil contaminated air filter is quite rare. Replacement intervals can be similar to that of spark plugs and again a quick inspection is all that may be required.
Aside from the other items listed in the weekly checks section that’s an engine bay service done and dusted.