Joe, a PPI (pre-purchase inspection) at a local MB dealer would have shown you exactly what repairs this E550 needs to make it right. From what I know the airmatic repairs are $1,200 - $1,500 per corner. The coil-over approach is worth considering, but the car will not perform the same … and it may take some computer re-programming for the car to assimilate the suspension modification.

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Fred Hoelzle