What does regular servicing entail?

There are always the comments about make sure it has been serviced properly, on a normal car what does servicing consist of? Not all of these every time of course.

Oil & filter change
Flush radiator - new coolant
Replace brake fluid - bleed
Replace clutch fluid - bleed
Auto trans service
Change gearbox oil
Change diff fluid
Replace fuel filter
Replace air filter
Clean/replace sparkplugs
Check brake pads, tyre pressure.

What else is an easily overlooked thing?

That's most of it, from there it tends to become fairly model specific.

Cabin filters, while not harmful to the car when left are a health hazard so should be changed every 12 months.

Timing belt, tensioners, waterpump service for belt driven vehicles. Some cars have balance belts that you would want to change at the same time too. Then there are the likes of some modern Toyota Diesels where you change injector seals and are best to inspect the oil pickup etc.

Personally, I change my fuel pump around 160'000km for peace of mind and also tend to do alternator clutch pulley, belt and tensioner around the same time too.

But really, just follow the manufacturers instructions for the specific vehicle and also check to see if there is any extra "good practice" service requirements. By that I mean a lot of manufacturers tried to specify "lifetime" coolant and transmission fluid. It doesn't really work in practice.

Also watch out for "service packages" which many garages offer (including dealerships who should know better). They are often glorified oil changes, where they change the oil and then just top up or "check" items that really should be changed. In my opinion it's really a scam that should be stopped, if you are not performing the manufacturers minimum specified service, it should never be allowed to be called a "service" in my opinion. Let alone a "comprehensive" or "full" service as some make out this to be.

Hope that helps.

spark plugs are never cleaned that was 100 years ago, thats replace only now depending on plugs longlive are 100.000km plugs

A battery test, terminal check and drive belt(s) inspection is also important, and belt tension in the case of manually tensioned belts. Especially at this time of year. Spark plugs are not cleaned as part of service any longer and pretty much haven't been since the 1970's, on a lot of engines its simply too labour intensive to do this, they are replaced at specific km intervals depending on type fitted. If a plug or plugs foul on a modern lean burn engine there is another reason for it which needs fixing.

I wonder at that. Simply removing them would put the vehicle into the same situation as all cars a couple of decades ago. I don't recall people getting sick as a result of not having them.

Of course the health of the filter companies would suffer.

Some vehicles have provision for cabin filters in the heater unit but are not equipped with them in the plant, they're dealer fitted accessories. The most common consequence of blocked filters is greatly reduced airflow out of the vents. They are good in the sense they keep a lot of dust and leaves from getting stuck behind the vents and keep the cabin more dust free but in metal road/farming environments they block up too quick and usually just get removed again.

I remove them from all of my cars and don't replace. Never had an issue.

Well hey, if you are really that desperate to save $10 a year by all means.

Personally, I enjoy a dust free interior without the nuisance of smelling diesel/petrol exhaust fumes and pollen irritating my eyes at certain times of the year.

BTW. the health hazard part is not just the lack of exhaust fumes but also if you leave it in and don't change it they can become a breeding ground for bacteria.

Mine usually entails parting with about $1500.00.

Where is the best place to get a $10 cabin filter?

Mine cost $70 a pair on here.

Jazz is probably using the stuff that came with his vacuum cleaner bags :D

Darn you got me wondering where it is on my current car. Time to look!

Back to op question, what does regular serving entail.

For me the list in second post is great and is a comprehensive service.
How often it is done is a debatable topic I guess.
I get a basic service done every 10,000 km with oil, oil filter, diagnostic check if relevant to car, and check everything else. I think many consider that ok for cars over 5 years old.
Ideally the comprehensive service would be every second service but I don't think everyone would do it that often, especially not on older cars of lesser value.