Man, am I glad I googled 'sliding noise in BMW E92' and found this thread.
That sliding noise was driving me nuts! ...for the life of me, I couldn't find the source!
First I removed the back panel on the drivers seat thinking something was loose inside the seat...then I removed the back seats thinking something under the rear bench...then the trunk liners to look at the upper rear shock mounts...nothing! So discouraged...thinking I'm going to have to go to the dealer and pay mucho bucks for a new rear end.
Then I searched and found this thread. WOOOOHOOO....I used my Milwaukee Inspection tool to look inside of the underseat vent and LOW AND BEHOLD....my long lost spark plug socket that disappeared some time around when the shuffling started!! ...it's been shuffling left and right , forward and back for months! Can you beleive it? It had to have entered those small vents perfectly like a heat seeking missile entering Bin Laden's window to get into there.
Praise be google and forums like this!
