Manifold/header/muffler/tail Pipe problems of the 2007 Mercedes Benz S550

My last two vehicles have been a 2007 mercedes S550. My first one operated well until the last 6-months that I had it. During that time, I had six visits and $5000+ in repairs, before a freak flood totaled the car. I used the insurance money and purchased a second car, identical to the first. I have not even made the first payment, and the car has been diagnosed with a gasket leak between the upper / lower intake manifold. This is a molded gasket and is not field replaceable. The entire manifold must be replaced at $2000. In my research, it has been discovered that this has been a known issue with mercedes, but they refuse to issue a recall to correct the problem. Instead, they allow the warranty to expire and allow the consumer to pay for the bill. I have contacted Mercedes Benz USA and they refuse to provide any compensation or even acknowledge that it is a known issue. This is totally unacceptable and shows a lack of committment by mercedes to stand behind their product. I might point out that they only have 48 month / 50k warranty, which is very low to other vehicles which have a standard 10 year / 100k warranty. This tells me that mercedes does not have the faith in their cars to increase the warranty. This is a car that cost 100k new and one would expect a better warranty and support from a company that touts their cars as being the best. I can tell you that I will never buy another mercedes or step foot into a dealership. On that note, I caught my local dealership attempting to overcharge me on a part by $400. Once I proved what other dealers where charging, they made an excuse and gave me the part at the rate that the other dealership was charging. What a shame. Buyer beware!!!.