Perhaps would take most of a day. Or more. There is some chance many things have never been cleaned and lubricated since these cars where new. I actually think besides being generally beneficial. We should start compiling a comprehensive list if one does not exist.

You need something most of us do not have. A point grease gun or fitting to get the door hinges. All the grease on the window regulators will be shot by now in most cases. Silicone lubrication of the window slides will make the system operate better and provide less operational stress on the power window system. Potentially prolonging the life of the components as well. Even the door seals should be lubricated or treated.

The hood hinge points. Especially those bushings and pins way back can seize otherwise. You will be sorry if they do.. The front hood latch and perhaps the hood cable as well. Then there is the sunroof slides to clean and lubricate. Plus the roof cable. When was the last time the front wheel bearings where repacked? This is just a start as all the door latch system is also probably pretty dry. All the throttle linkage parts.

We can cover the right lubricants to use as well in different applications. There will be issues in many cases. Like the door hinges not taking grease. So penetrating oil will have to be injected first in some cases. Excess wear in throttle linkage components if found. The Ball joints should still be available new or you can tell if they are still good on a car at the wrecking yard. Probably on gas as well as diesel cars.

I read somewhere that an individual had figured out just what the special Mercedes sunroof grease was. I believe he found the same product at a much cheaper price. I am going to have to search for that one as I both forget what it was and where I read about it. Possibly a thin silicone grease as it does not dry out. As normal grease tends to do with time.

It did occur to me that most sunroofs of many brands would need their sliding rails treated from time to time. So what do those brands recommend as a lubricant? Certainly not the Mercedes product. Also in the process we would build up a supply of many different types of lubricants.

I know I am going to the shelf myself frequently enough to grab what I think is needed for a certain application. That is often enough not car related in application. Silicone based greases for example are far superior to normal greases. In many applications. The checking and lubrication of the calipers so the brake pads are really free. The standard transmissions and rear ends. Might warrant consideration. At least a fluid level check.

Rear outer cv joints also may need a shot of heavy normal oil as a preventative measure. I know I am missing some things that should be addressed lubrication wise. In many cases it will make the car even seem better to the owner. Plus as you go along you may turn up something that really should be addressed. Before it evolves into a real issue.