i believe it took my MB-guru approx 5-6 hrs IIRC?
he had to remove the inner C-pillar panels, drivers chair beneath the carpet for grounding the powerloom.
remove bottom panels running the loom
cutting the new shelf for speakerholes, backseat latches, fitting 3rd brakelight etc etc
it took him some time to do this for me.
I know how much he loves working on my car, doing special mods