Not 'extra" parts, they are parts used before a re-design in 2006.
You removed the parts that enable what is called "the redundant lock" function. (Stupid name for it, it's not redundant)

Picture this:
When you insert your key and turn it to "ON", the plunger is pulled out of the steering column that locks the wheel.
When you turn the key "OFF", nothing happens. When you REMOVE the key, the plunger extends, locking the wheel. (You can HEAR this happen, if you listen closely.)

They put those two parts in there so that the plunger can't be 'pushed in' when in the "Off/Lock" position. So now, your plunger CAN be pushed in.
Is this a problem? NO, as you can see, there is NO WAY for anyone to PUSH it in anyway. Hence, we think of those two parts as "extra". Even MB thought so, sometime in 2006, they stopped building the cars with those two parts. So you see, any late 06, and any 07-08 cars don't have those parts.