A couple of times I have noticed this sort of aggressive steering wheel vibrations when im reversing from parked position and fully lock the steering wheel? Any ideas on what could be causing this.

Sorry for all the Qs just trying to make sure everything is cool.

 

So it doesn't seem to vibrate when locking the wheel when brake is applied but definitely an abrupt vibration when reversing slowing while turning the wheel towards locked position.

 

Is it on concrete or asphalt when it happens? I've noticed mine hops a bit on concrete closer to lock when moving.

 

Yep, some report "tire skip" at low speed on full lock, doesn't matter whether it's going forward or backwards or left or right lock, but the surface appears to make a difference.
Apparently it's normal/common, although I have never experienced it, see this thread: Creek on full lock

 

Stop holding your steering wheels at full lock...lol "If it hurts when you do that, stop doing that"...lol
Seriously, holding the wheel at lock only puts strain on the PS pump and its pressure relief valve.