Having owned a used 1994 E320 Wagon for several years, I can tell you that the Starmark warranty is well worth it. The only problems my wagon has experienced, though, are the same issues of the sedan and coupe. In addition to the items listed above, I’ve had to replace the climate control fan (big job), the O2 sensor, the mass airflow sensor, and the sway bar bushings. Nothing unique to it being a wagon has come up.
If your wagon does not come with these options, consider asking the dealer to include them at no additional cost: Cargo cover/net (I found out the hard way that, unless you find a matching, salvaged cover/net, the oe dealer cost is approximately $1,000, CD changer, upgraded Michelin tires, and cup holders.
Overall, it’s by far the most practical, versatile vehicle I have ever owned. Its daily use is as kid hauler and grocery getter. On weekends I use it as the world’s most luxurious pickup truck. While it excels at both these functions, it really shines as grand touring/family vacation transportation.
1988 300 SL (5 Speed)
1994 E320 Wagon