I bought my 1997 S500 a couple of weeks ago and have been sorting through its faults. It has the self leveling rear suspension and it was "bouncy." We couldn't find anything leaking in the rear but I still had nightmares over what it would cost to fix. We then checked the power steering fluid level and it was low, barely touching the dip stick. Adding about 3 ounces of fluid brought it up the the mark and the bounce went out of the suspension! Hurray!

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2000 Mercedes S500
1990 Mercedes 560SEL
1970 Triumph Spitfire