First of all welcome to Nico!
I owned a G35 in the past.
I seem to remember a bit of that. It depends how much of a jerk you are talking about.
When the car is idling high from startup and putting it in D or R I do feel a bit of a quick pull in that direction even with the foot on the break.
My XTerra (same transmission almost same engine) does it also.
I thought it was normal.
But how big is that "jerk"?
I think thats important.. if u post a vid maybe..