The most unreliable vehicle I have ever owned has been my 1998 ML-320.
This truck has had numerous problems with the electrical system and the
engine. The engine was replaced with a new one in January 2002. From
December 1999 to January 2002, this truck was in the "shop" about 15
times for various problems. MB North America paid for the new engine, as
the manufacturer's warranty had just expired. Lucky for me, as I would have
never had the means or desire to purchase a new engine for this truck. The
best that I can say about this truck is that it hasn't returned for repairs since
the new engine was installed.