Seems like $4,600 for what is essentially a 2 year warranty is pretty high. When I picked up my E350 MY2010 the cost of a warranty was about $1,750 (100K / 7 years). Due to the fact I do not drive that kind of miles (7K is usually tops in annual millage for me) it would not have paid to do so (Time would have negated the warranty long before the millage did). I understand they can also be purchased from MB at any time before expiration of the OEM warranty.