I'm experiencing a rear suspension noise at low speeds, the car (2001 C240) has 84,000 miles and I narrowed my search for culprit to rear shock absorber. How do I get to the upper mounting bolt? Do I need to remove C-pillar interior trim? Factory manual is silent about this.
Please can somebody help.

Thanks.

Do I remove the rear seats? Seat cushion and then backrest? Is the shock upper mounting located there?

Don't know about the C-240, but, the older vehicles require you to remove the rear seat to access the top nuts for the shock.

I'd bet that it's similar.