My wife came home tonight, and I noticed that her 06 R350 is listing heavily to the passenger side, evenly front and rear. It does not have the airmatic suspension (one of the reasons I liked this particular 350 when I bought it).

What causes this? What's the fix?

Even though you do not have 4-wheel Airmatic, you do have self leveling air suspension in the rear (all U.S. market R-class cars had either rear air suspension or full Airmatic). So, your right-rear air spring is leaking. Best to replace in pairs (since the other one will also start leaking), and it's an easy job, so just order replacements here:

https://www.arnottindustries.com/par...18_pid190.html

Thanks - I guess I'll take it to my shop and have them look at it.