You may have to raise the seat up to it's highest position to get access to the rear bolts. Pull up on the handle on the side of the seat, and if necessary, have someone push the seat from behind, because it can get stuck after a few years of being inoperative.

-Joe

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.