This could be the issue but getting to it is difficult. and you can probably examine it if you get the car on a lift. The guibo is incredibly strong. A while back I had both BMW and an INDY tell me I had to replace the shifter bushings on the car and the INDY told me my driveshaft is bent and I might as well replace the flex disc too. So I got a new driveshaft and all the other goodies and did it. I did not have a press for the driveshaft so I took it locally and had them press it. They asked me why im changing it and i told them...they said nothing wrong with driveshaft and offered to buy it from me so what the hell I sold it because i alrready got a new one and had them take some sleeve from it. what a joke. So anyway I put it all back together and that was that. Didn't fix issue but I did have a short shifter that I put in there....I mean SHORT so that was cool until a few months later when someone smacked me and pushed my trunk into passenger seat. RIP
Point is... you may listen to people and spend a ton to never fix. If I were you, just do a visual inspection first before doing anything. Have you looked at your engine mounts. How is your stop and go do you feel any jerk or shake? Check into those, do a visual inspection.
What is the difference from when the car is creeping and moving? The engine is already in a "strained position" so you may not feel anything but if it's loose you would feel it while taking off or punching or stopping abruptly. The manifold is also electronically controlled. I do not know much about the 545 but I do know BMW and most of these cars have electronically controlled manifolds. At low RPM you are electronically limiting the manifold while when you are above 1000-1500 RPM you are most likely Fully Open. Think of a butterfly valve. I hope you get it sorted out.

 

Thanks for the advice. I will post updates whenever I can get around to looking into it.

 

Look at item 17 at that diagram - you will find where CV joint is on RWD vehicle you moron with 1000 useless posts.