John,

Not uncommon for a car which has a bad rear window seal and bad trunk seal. I've got the same problem on my '83 300SD but since it's the daily banger I'm not worrying about it. The other thing to watch on W126s (at least early ones) is rust on the lower rear control arms where the shock bolts to them. Again, my right rear a-arm on the SD is showing rust so I am going to be replacing it shortly. I will also re-rubber the other side to keep things equal. Probably will also put new shocks all around. The rear is beginning to show signs of needing new ones, so I will treat the front end as well.

Nothing better than a W126 with a fresh suspension.....Except of course a W116 with a fresh suspension!

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Regards,
Aaron