The Daimler-Benz AG era cars are the best and therefore deserve the best. These new ones are just junk. Chrysler products with Daimler Star. Yes Chrysler is not part of Mercedes-Benz anymore, but ever since Chrysler was involved Mercedes has not been the same. The customer service now is terrible, the roadside assistance has changed drastically only to cover new car buyers. Hect, I have the original 1987 S-Class sales brochure for my car and they could not stress but enough the superiority of their engineering. I say there was a time when Mercedes-Benz was in competition with Rolls Royce, and now Mercedes has to compete with Hyundai? What the hell is this s#$t!!
I look at it like this, when it was Daimler and Benz, Daimler-Benz AG it was good. Once Benz was removed it was junk. Even though the founders have been dead for a long time up until the end of Daimler-Benz their mission had lived on.
I think the "superiority" of the engineering is all but a myth. The only thing Mercedes did better than the competition was to over engineer things so that they would last longer, and hire a competent marketing team throughout the years to maintain the myth. They rust just as much as other cars of the era, they have the same brake problems as cars of the same era, etc etc. I'm sure you know this already Leidenschaft, but the Bosch fuel systems on the typical 108 of the early 70s also made its way to Volkswagen, Audi, Porsche, Fiat and Lancia. Does that pull Mercedes down also?
As for the pedestal you put Rolls Royce on, have you ever been in one or maintained one? Their maintenance records are worse than Mercedes. Aside from a plush interior and a snooty marque, Rolls is no better than anything else out there.
As for competing against Hyundai, you might do yourself a favor and take a ride in one. They aren't the rice burners of legend, and do indeed compare very favorably against any German car (which I can say also, having owned multiple German cars and Hyundais). I would suspect that if you looked at their stock, you'd see the company that offers a 100k mile warranty hasn't gone bankrupt with repair bills. Actually, I would think that the only major difference between the two is the elevation of the noses of the drivers, and the sticker price in getting it there.
It's been discussed on this thread multiple times, the mystique of a classic Benz, that is. While I'm a huge fan of the brand and have owned multiple models of the same, I get a hoot out of people suggesting paying stupidly high Mercedes-specific prices for a Mercedes-approved something or another. The MAF sensor in my BMW is about to bite it, and the stealership cost is more than 5 times what I'd pay for an equivalent part that comes with an equivalent warranty. And the labor cost for stealership folks to put the thing in is more than 3x that of the local indie guy who specializes in BMWs. The cost of a MAP sensor for our 108s at the stealership is WELL north of what I'd pay for an aftermarket part, again with a warranty. The ONLY thing you get from a stealership repair is a higher bill and the satisfaction that a part hidden under the hood has the company logo on it.
In the case of the appropriate grease for the aforementioned rails, a silicon grease will last years and will indeed attract dust. Like anything exposed to the elements, you'll need to maintain the thing with a couple hours worth of maintenance. That's it. If something German, or "approved" is a must have, then do some research and find a good Deutche chemical company and buy their product. Or go to (gasp) Autozone or Napa, and purchase something made by 3M. You know, the company that makes lubricants for NASA, Lockheed, etc etc. You'll pay $12 for enough of the product to lube the rails up and even have a bunch left over.