My daughters and son-in-laws late '97 E-420 has been good. Almost 200K since October 1997 and nothing major.
A good MBZ to get but not for everyone is a 2005-2006 E-320 CDI. Helps to be mechanically inclined
and to be able to do some things for yourself as they are expensive to simply take to the dealers, but there
are independants who are reasonable and it helps to be able to get parts at a discount also.
Nothing that size or with that performance can touch your fuel costs per mile.
Shop for a good used one and do not worry about how many miles are on the odometer.
A careful shopper should be able to find a good well-cared for model for less than $20K.
I am currently running ours for less than eleven ($.11) cents per mile for fuel.
Fuel economy is never less than 35 mpg!
Fuel is the highest in California, but like I said,compare the cost for fuel per mile.
Study my F E on Fuelly under all 2005 E-320 CDIs.
Unfortunately, you are in the possession of the range of bad cars MB built from about 1996 to 2002 or 03, except the W140
(which seemed to stabilize toward the end of its 1999 life), and the wonderful R129 (SL's), which was on a W124 chassis.
I stayed away for about 10 years. My opinion is that
1) MB was pre-occupied with Chrysler and
2) its experienced engineers retired and a "young", in-experienced group came in.
The 96, 97,98 E classes were particularly bad (apologies, if offended any of those owners), with terrible crash test
results and funky other stuff. I hope that does not include the M113 V8, since I have that in my 2000 SL5000.
I have never read how the M113 3v was better than the M119 4v.
At any rate, proof anyone can bad cars. However, as of 2007-9, MB had recovered and was building some very nice cars.
Caveat, I don't like the follow-on to the R129, in any number of ways. The R129 I will be keeping forever. Oh, well.