E60 530d slight rock on acceleration

Hi folks.

My car has had an issue since I bought it which is a bit strange and I'm wondering if anyone has come across this issue before.
Basically under light acceleration say when driving around a car park, when the accelerator is pressed lightly say when pushing on and then depressed I can feel a rocking sensation but I'm unable to pinpoint where the rocking sensation is coming from.
It only happens at low speeds under 40mph when pressing and depressing the accelerator but it is there whether the car is cold or warmed up.
I've replaced the shocks, springs, most of the suspension up front, wheels have been refurbed and the car has brand new tyres, autobox has been serviced and car changes gears up and down perfectly and no codes are stored so I'm clueless as to where to start really.
Has anyone come across this before?
Could a worn propshaft or engine mounts cause this rocking sensation?
Cheers

Gearbox mounts, propshaft guibo or engine mounts would be were I would look.


Or the propshaft universal.

Hi Dave. Would the gearbox mounts be replaced during an autobox service usually? Had the box done at autotranz earlier in the year so will need to check with them. Thing is it doesn't happen during gear changes so would that rule out gearbox mounts?