There is a 'feature' which drives the passenger seat forward when the rear seat is folded in the W211 T . But this stops you moving the passenger front seat back and forth.
I have tried re-setting the adjustment (Position 2 on ignition and push seat adjuster forward hold for 3 seconds then push back and repeat) didn't work.
But if you put your finger in the locking latch slot in the folded back of the backseat you can pull the latch forward and hear a click. The seat thinks it is locked and you can drive the front seat backwards with the door switches.
I have tried re-setting the adjustment (Position 2 on ignition and push seat adjuster forward hold for 3 seconds then push back and repeat) didn't work.
But if you put your finger in the locking latch slot in the folded back of the backseat you can pull the latch forward and hear a click. The seat thinks it is locked and you can drive the front seat backwards with the door switches.