We bought GE extended warranty coverage on our 92 300E, and our 94 wagon is Starmark'd, and all I can say is that the money spent on these warranties was some of the best money we have ever spent. On the 300E the warranty paid for itself at least 3 times over (had the dreaded air conditioning rebuild, head gasket replacement, valve guide replacement, etc.), and on the wagon it has paid for itself at least once already, with another year and a half yet to go.
We love our Benz's but they can be very expensive to maintain....
92 300E (Black/Grey interior: wife's car)
94 E320 Wagon (White/Saddle interior, Eibach springs, '96 E420 16 x 7.5 wheels)